Nipples from the cold. Why are women's nipples large? Women have more than two nipples - sometimes it happens

So, if you notice that...


BREASTS INCREASE

1. You are gaining weight

After puberty, breasts grow as the rest of the body grows. Why does my weight increase? You may eat more, exercise less, sleep little, or live under stress. Plus or minus a kilogram is natural. If you gain more weight, your risk of getting cancer increases.

2. You are expecting your period, have started taking oral contraceptives or are pregnant

Hormones affect breast size. If both breasts are enlarged, there is nothing to worry about.


BREASTS ARE SMALLER

3. You are losing weight

Breasts are made up of fat, so if you are losing weight, they will be the first body part you notice. If your weight and breasts decrease without visible reasons, you should see a doctor. After all, it could be hyperthyroidism or another disease.

4. New menstrual cycle

If the breasts increase before menstruation, it means that after it the swelling will go away and they will decrease. There is no reason to worry.


ONE BREAST IS BIGGER THAN THE OTHER

5. Nothing special

Breasts are not symmetrical, so if they have always been different size and shape, everything is fine.

6. Breast cancer

If the shape of one breast is changing, it's time to get checked for breast cancer.


IRRITATION TO THE SKIN UNDER THE BREASTS

7. Allergies

This happens when your bra wires are made of nickel, the soap didn't wash off after swimming, or you wore a sweater that irritates your skin. Hydrocortisone ointment will help you. If the irritation does not go away after a few days, see a doctor.

8. Intertriginous dermatitis

Or diaper rash. Very often in summer the skin under the breasts becomes chafed and inflamed. An antibiotic, steroid or hydrocortisone ointment will relieve the irritation, and a properly fitted bra will support your breasts and prevent recurrence.

9. The linen is no longer fresh.

Infrequent washing actually preserves the laundry, but bacteria or fungi can settle in it. The skin under the breasts sweats a lot and this is very beneficial for them.


YOU HAVE NOTICEABLE STRETCH MARKS

10. Your weight is fluctuating.

As your weight fluctuates, your breasts grow and shrink. This causes stretch marks. This often happens after pregnancy and in women with thin, inelastic skin.


VERY DARK OR LIGHT NIPPLES

11. Nothing special

No, it's not cancer. Each woman's nipples are colored differently. The main thing is that it is symmetrical.


VERY LARGE OR SMALL NIPPLES

12. Nothing special

Our bodies are simply different. If they are symmetrical, there is no problem.


BUBBLES ON AREOLAS

13. Nothing special

Breasts are intended for feeding babies. These tubercles are the exits of the milk ducts. Sometimes they get a little bigger, so if there are small bumps surrounding your nipple, you're fine.


ONE LARGE BUMPLE ON THE AREOLA

14. Benign cyst or malignancy

Get tested as soon as possible to find out if there is any cause for concern.


HAIR AROUND THE NIPPLE

15. Polycystic ovary syndrome

If you have started to grow hair around your nipple, your testosterone levels may have increased due to PCOS. Other symptoms include acne and irregular periods. Polycystic disease can lead to infertility, so you should see a doctor.


NIPPLES ITCH

16. Shampoo or soap residue irritates the skin.

Rinse your skin with water and apply hydrocortisone ointment.

17. Allergy to clothes

This could be a reaction to the dye in a new bra or wool sweater. Apply hydrocortisone ointment to your nipples and change your clothes.

18. A new cycle will begin soon

Sometimes hormonal changes cause itching.

19. Paget's disease

Or breast cancer, a very rare disease. Its symptoms are itchy nipples and areolas, flaky skin, a flattened nipple and yellow or bloody issues from the nipple. See a doctor immediately.


PAIN AND LAMPS IN THE CHEST

20. A new cycle will begin soon

Depending on the phase of the cycle, the structure and sensitivity of the breast may change. You should see a doctor. One consolation is that if you have bumps but no pain, then most likely it is not a tumor.

21. Too much caffeine

Caffeine causes chest pain for some people, so just start drinking less coffee, tea and soda and the problem will go away.


WHITE CLOUDY DISCHARGE FROM NIPPLES

22. Something stimulates milk production

Breasts are needed to feed babies. If the discharge looks like milk, something may be stimulating your milk production, even if you are not pregnant or caring for a small baby. The doctor will choose a medicine for you.

23. By-effect antidepressants or antipsychotics

Some medications increase levels of prolactin, a hormone that stimulates milk production. In most cases, this is done safely, although it is unpleasant.


OTHER DISCHARGES FROM THE NIPLE

24. Benign neoplasm

Known as papilloma. You should see a doctor.


NIPPLES HARD

25. You're excited

If your nipples are symmetrical but firm, there is nothing to worry about. The muscles around the nipple simply contracted. This is usually related to sex.

26. You are cold

If it's not about sex, then the simplest explanation is cold. Just stay warm.


Inverted Nipple OR Dimples in the Nipple or BREAST

27. Breast cancer

Any dents could be a sign of cancer. You should see a doctor URGENTLY.


LAMP IN THE CHEST

28. Everything is fine with you

Now it’s just another phase of the cycle when the breasts become denser. This is fine. Breast lumps that could mean something serious can only be detected with a mammogram.


VEINS VISIBLE THROUGH THE SKIN

29. Risk of skin cancer

Fair skin is usually pale and translucent. If so, you are at high risk sunburn, but as long as you don’t overuse tanning and use sunscreens, there will be no serious problems.


BREASTS LOOK LIKE ORANGES

30. Breast cancer

If your smooth breasts suddenly become uneven like an orange peel, and your areolas and nipples become hard, it may be cancer. You should see a doctor URGENTLY.


BUNE ON THE CHEST

31. Benign cyst

If it is round and smooth and you can move it, it may be a benign cyst filled with fluid. It's not a tumor. You should see a doctor.

32. Breast cancer

Most often, pain and growths in the chest are the result of hormones. Every time you encounter them, the question arises: is it cancer or could it become cancer? Only the doctor will answer.

Despite the fact that it is the 21st century and many issues have long been discussed openly and without embarrassment, there are still some nuances that we still talk about “in a whisper.”

We often turn to the online community for help, wanting to simultaneously satisfy our interest and remain incognito. Among such intimate questions, you can find a desire to know more about the reasons why nipples stand and how this happens.

Simple physiology: how does nipple erection occur?

Each of us visually has a very good idea of ​​our breasts. At the same time, clearly distinguishing and defining: this is a man’s breast, and this is a woman’s. But not everyone knows that the chest contains many nerve endings that are located around muscle structures.

External stimuli provoke contraction of these muscle fibers, which ultimately leads to erection of the nipples.

So, for example, speaking about physical arousal, the mechanism of “nipple erection” can be described approximately like this:

  1. Touching causes irritation of nerve endings.
  2. During this process, a nerve impulse is formed and sent to the brain.
  3. After it is processed by the brain, there is an increase in blood flow to the mammary glands, including to the nipples.
  4. As a result, the nipples harden and “stand up.”

If changes in the breast occur due to cold, then the essence of nipple erection in this case comes down to spasms of muscle fibers that form goosebumps on the skin: the muscles contract and a change in shape, and sometimes even the color of the nipple, as well as the skin around it, occurs.

When is nipple erection a normal reflex?

So, you ask: are nipple hardening always normal? And what is “the norm” in this case, and what is a deviation from it?

The answers to these and other questions are contained in the reasons for erect nipples and, oddly enough, in the frequency of repetitions of this reaction. In this case, you should be especially attentive to the fact that the “female” reasons are somewhat different from the “male” ones.

What can cause nipple erection in women?

The reasons for erect nipples in women include:

Temperature changes

Many people have probably noticed that due to a decrease in air or water temperature, women's nipples become sensitive and stick out - this is a standard reaction to cold. However, this effect is not achieved by a gradual decrease in temperature, but by sudden changes, which in most cases are unpleasant and uncomfortable for the female body.

Sexual desire

Anticipation of sex, foreplay/preparation for sexual intercourse, sex itself is the most common cause of hardened nipples, and one of the main signs (indicators) of arousal in women, often confirming pleasure from the process. Most often it occurs as a reaction to stroking and touching.

Pregnancy period

During pregnancy, breasts generally change. Naturally, both the nipples and areola change. Nipples may increase in size, become rough, and their sensitivity increases.

In some cases it is possible painful sensations in the entire breast, or individual parts, including the nipples. There is no need to worry about this - most often this is a normal physiological reaction to changes occurring in the body. But, if you notice that the pain is getting worse, then you should urgently consult a doctor for diagnosis and treatment.

Premenstrual syndrome

Nipple sensitivity can be one of the symptoms of PMS. Before the start of a new menstrual cycle (on the eve of the menstrual period), many women’s breasts seem to swell, gain weight, they note an increase in the sensitivity of the nipples, and that they can periodically stand up.

As with pregnancy, you should not rush to the hospital at the slightest change. But if the sensitivity of the nipples is accompanied by pain, which remains even after menstruation, then you should not delay visiting a specialist. Remember, the diagnosis will ensure timely treatment of the mammary glands.

Incorrectly selected underwear

If the bra size is larger than the girl needs, the nipples can rub against its inner surface, harden, become rough and “stand up”.

Spontaneous nipple erection

This happens rarely and not for all women. This reaction is not associated with thoughts, feelings or sensations. Usually does not last long, but at the same time it may recur throughout the day.

Psychological state/nervous agitation/tension

Individual characteristics of the nervous system can sometimes be expressed in the fact that a woman’s breasts harden and her nipples “stand up.”

What reasons can cause hard nipples in men?

The reasons for erect male nipples can be described as follows:

Excitation

This is where nipple hardening in men converges with women's reaction to sex. Sometimes nipples can be one of a man’s strong erogenous zones, although this is considered rare and does not occur in everyone.

Puberty

Nipples may become hard due to hormonal changes. As you know, the reactions of a teenager’s body during puberty are unstable, therefore erection of the nipples can occur completely arbitrarily, either for a couple of minutes or for a longer time.

Intoxication

When the level of alcohol in the blood exceeds, men often have nipples that stick out, but the areolas decrease in size.

Temperature changes

Erection of the nipples can occur from cold: be a reaction to interaction with ice, cold water and cold objects.

Diseases

In some cases, “raised” nipples in a man indicate the presence of viruses in the body or are a consequence of an inflammatory process in the body. During self-examination, you need to pay attention to whether there are any discharges from the chest, especially purulent ones.

If they are available, you need to make an appointment with a doctor as soon as possible, without postponing the visit.

In what cases should you urgently visit a doctor?

Having studied the reasons for erect nipples, we can say that almost all of them are normal and harmless. Don't panic, get upset or embarrassed if your nipples become erect - this is physiology. But there are still cases when you need to pay close attention to your body.

We have already mentioned discharge from the nipples above - if there is any, then you should consult a doctor immediately. In addition, evidence of ill health can include itching in the nipples, redness or other changes noticeable during self-examination.

It is advisable to describe such deviations by seeking help and advice from a specialist.

Remember that when it comes to health, it is better to play it safe and rule out a disease than to ignore a seemingly insignificant symptom and trigger the disease.

Video: what should healthy nipples look like?

The most sensitive part of a woman's body is the mammary glands. There is often a feeling of discomfort in this area. It’s worth talking in more detail about why nipples get hard.

Obvious reasons

Specialists in the field of gynecology identify several reasons why women's nipples become hard:

  1. Due to prolonged stress. As you know, a huge number of nerve endings are concentrated in the chest. If a young mother is nervous for a long time, then her milk disappears. Other women's nipples begin to harden.
  2. Changes in hormonal levels.
  3. Viral disease. In many females, when body temperature rises, the mammary glands may change.
  4. Strong excitement.
  5. Nipples can shrink and harden from any tactile touch.

Gynecologists claim that the most common cause of this symptom is early stage pregnancy.

Breast response to stimulation

As mentioned earlier, there are several reasons why female nipples become hard. It is worth taking a closer look at each of them.

Every body reacts differently to sexual intercourse. The mammary glands can change in some due to strong, in others due to mild excitement. And for some representatives of the fair sex they remain in the same state.

Why do nipples get hard when aroused? This is due to the intense production of endorphins - joy hormones. If a man sees that his partner’s areolas have shrunk, that the skin has acquired a rough outline, then he can be sure that he is doing everything right.

Emotional factor or illness

A less common reason why nipples become hard is stress. This change occurs in approximately three percent of women. The human body can be sensitive to worries and experiences. This leads to hormonal imbalance, and subsequently to changes in the menstrual cycle and changes appearance nipples

Any disease is also a great stress for the body. Many young mothers have weakened immune systems during lactation. As the body temperature rises, some of them experience stagnation of milk and begin to harden, swell and turn red.

First sign of pregnancy

It is inherent in nature that a woman’s body is designed to create new life. As soon as the egg is fertilized, he begins to prepare for bearing the fetus. Many symptoms can notify the expectant mother of her interesting situation faster than experienced specialists or modern diagnostic equipment can do.

An obvious symptom is a change in the appearance of the nipples. They become darker, harden and swell. Often there is a feeling of discomfort and mild pain in this area. A woman may feel that her bust has even become one size larger.

What is this connected with? The body naturally prepares for postpartum lactation. Accordingly, an expansion of the mammary duct is formed. In 70 percent of women this occurs in the first trimester of pregnancy, in 25 percent in the second and third, the remaining 5 percent do not feel any changes during pregnancy.

Effect on tactile contact or individual characteristic

Many women are interested in why their nipples get hard even from a light touch. The skin in this area becomes wrinkled and rough. This protective reaction is an individual feature of the body. Some ladies experience a similar symptom:

  • Due to temperature fluctuations. For example, if a woman after hot bath dive into an ice hole; will go out of the house into the cold street in light clothing. Any sudden change temperature regime leads to similar changes.
  • Because of physical activity. About 2 percent of women experience muscle spasms during exercise. The condition of the halos will recover on its own, 10-15 minutes after a grueling workout.
  • In almost 70 percent of women, nipples become hard and sore due to changes in hormonal levels in the body. This often occurs before menstruation or ovulation.

There is also a less common feature of the body when the breasts always have a compacted structure with hard nipples. Women live with this throughout their lives, and it does not bother them at all.

Incorrect choice

Why do nipples often get hard and hurt? Surprisingly, this symptom can also be associated with allergies. For example, if a female representative wears clothes made of poor quality material. Some ladies like to wear a bra one or two sizes smaller than the original one to make their dignity even more expressive. Because of this, a similar illness may also appear.

There's no reason to worry

As it has already turned out, there are a number of reasons why women’s nipples become hard. This phenomenon is absolutely normal if:

  • The pain is moderate. Has the same character throughout the day. Doesn't get worse over time.
  • There are no additional symptoms.
  • The pain is present for no more than three days.
  • No swelling.
  • No redness.

The absolute norm is such a symptom during pregnancy, ovulation, lactation and before menstrual cycle. In all of the above cases, specialist help is not required. Mild discomfort can be relieved by massaging the area with smooth movements and taking a warm shower.

Need specialist help

Sometimes hard nipples can be the primary symptom of a serious illness. You should seek the help of a specialist if the following symptoms appear:

  1. If the discomfort constantly gets worse. Subsequently, it is expressed by acute, barely bearable pain.
  2. When additional characteristic signs appear: fever, redness, erosion, swelling.
  3. With simultaneous pain in other areas of the body.
  4. If there is any discharge from the nipples. The exception is lactation or pregnancy.
  5. When a lump is detected in the chest area.

You should be wary if the above symptoms appear simultaneously with hardening of your nipples. They can become a harbinger of a serious illness, ranging from mastitis to cancer. You need to do the following:

  • Come for a consultation with a therapist, mammologist or gynecologist.
  • Pass a number of standard tests: urine, feces, clinical blood test.
  • Do ultrasonography(ultrasound).
  • Get a mammogram.
  • If necessary, an additional biopsy is prescribed to detect cancer cells.

A number of studies will eliminate the risk of developing a serious disease in the early stages.

What about men?

The question of why nipples get hard worries women more. This does not mean that men do not encounter similar phenomena. They may experience a similar symptom in the following cases:

  • With strong excitement.
  • While intoxicated.
  • This often occurs in adolescents during puberty.

This symptom, just like in women, can be a harbinger of a serious illness.

Conclusion

There are a huge number of both harmless and serious reasons why nipples become hard. Listen to your body. Assess the nature of the pain. Analyze your condition for additional symptoms. All this will allow you to determine whether such a symptom is normal or whether it’s time to contact a specialist.

The female body is very mysterious and includes many processes that directly depend on hormonal levels. This also affects the sensitivity of the nipples. But what else can cause their increased susceptibility, what are the reasons for this phenomenon and is it related to pathologies.

What is nipple sensitivity

The nipples are riddled with various receptors and endings that respond to touch and all kinds of irritants. Most women may not feel anything when lightly stroked, but for some, any contact with external factors triggers a reaction. What could this depend on and why do nipples suddenly become overly sensitive? Reasons why this may happen:

  1. During the period of PMS.
  2. During menstruation itself.
  3. Pregnancy.
  4. While breastfeeding.

This is when the mammary glands and nipples begin to swell due to the excess flow of blood plasma. This is why the sensitivity of the nipples and breasts increases.

Pregnancy

Sensitive nipples usually during pregnancy. Statistics say that 80% of the manifestations of excessive susceptibility of this zone in women occur even at very early stages, because hormonal background begins to experience enormous changes. They become such in order to protect the reproductive organ from interrupting the development of the child, since oxytocin is produced when the breast is stimulated. This hormone is responsible for contractions of the uterus. When this area becomes sensitive and it is painful to touch the nipples, it is advisable for the woman to avoid stimulation of the mammary glands, which has a beneficial effect on the course of pregnancy, especially when it is in the early stages.

Naturally, it will not be possible to avoid such changes, so this discomfort will have to be endured. To alleviate this factor, you can change the bra to fit your existing breast size and be made from natural fabrics.


Nipple sensitivity increases due to breastfeeding. At this moment, they not only react to touch, but also hurt a lot. The reasons for this are the incorrect position of the child or mother, simultaneous feeding from a bottle and breastfeeding forms improper sucking. Pain may also occur due to untimely replacement of the chest pad. This increases the moisture content of the skin on the nipples, making them overly soft. Pain can provoke inept termination of the feeding process and separation of the baby from the mother's breast.

Dry, sore, or irritated nipples may cause these symptoms. Also, don’t forget about uncomfortable underwear. At the time of breastfeeding, it is better to give preference to natural materials that were used during pregnancy.

PMS

Women's nipples become very sensitive before menstruation. Why is this happening? In the second phase of the cycle, when ovulation has already passed, progesterone begins to be actively produced. This hormone allows the endometrium to thicken to the required thickness and preserve the fetus. This substance reaches its peak 7 days after the start of the second phase. Then women begin to notice that their nipples have become much more sensitive, and their breasts have increased slightly. Such reasons are often confused with pregnancy symptoms, but over time everything falls into place.

Ovulation

If your nipples suddenly become sensitive, this may indicate the onset of ovulation, when the egg leaves the ovary. The reasons also lie in hormones. In the first phases, the presence of estrogen is more dominant. It allows the follicle to grow and affects the endometrium. At such a time, the female breast is the softest and most relaxed, and when the middle of the cycle approaches, the body feels the beginning of reformation. A latinizing hormone is released, which affects the rupture of the follicle and egg rejection. At the same time, this substance affects the woman’s breasts. This is why she becomes more aroused and her nipples and areolas are very receptive.

Important! This factor occurs only in the middle of the cycle, so it cannot be confused with pregnancy or PMS.

Presence of pathologies

Nipple sensitivity increases if female body with some pathological processes. Often this symptom occurs when the patient suffers from hormonal ailments:

  • Uterine fibroids.
  • Polycystic disease, etc.

Also, the fact that nipples have become more receptive can be affected by the presence of tumors in the mammary glands. At the same time, an increase or deformation of the shape of the breast is observed, and the painful sensations do not give rest for a long period and become more acute each time.

Mastopathy and other diseases of the mammary glands can cause sensitivity in this area. Such pathologies do not pose a particular threat to the health and life of a woman, but require immediate specialized intervention. Since without adequate timely treatment they can develop into tumors or acquire other complicated forms.

Individual predispositions

Nipple sensitivity may be explained individual characteristics human body and skin. The causes of manifestation arise during puberty and are present on an ongoing basis. It is worth noting that there are very few such women, but at the same time they work and live normally, since the susceptibility of this area does not bring them discomfort.

Conclusion

When pain and sensitivity last for a long time, it is necessary to consult a specialist and undergo diagnostic procedures in order to rule out the presence of diseases. If this is related to hormones, the doctor will prescribe medications and a special diet. We should also not forget about the psychological aspect: negative emotions, stressful situations, conflicts arising in intimate terms, etc.

If there is a need to take oral contraceptives, then before using them you need to consult a doctor who will recommend a suitable drug. You should also properly care for the skin of your breasts and nipples, using hypoallergenic products and gels for intimate hygiene.

Flat or inverted nipples (which seem to be hidden in the chest) occur in both men and women. This problem has many potential causes: some people have it since birth, while others develop it due to certain medical conditions. If you haven't had flat nipples since childhood or adolescence, and you notice any signs of this problem, then you should contact a specialist. If you are over 50 years of age and notice changes in the shape of your nipples, you should immediately contact your doctor and be tested for breast cancer. In general, inverted nipples can cause both inconvenience for aesthetic reasons and, in more complex cases, be difficult to treat. breastfeeding. Fortunately, there are ways to solve this problem, ranging from manual stimulation to plastic surgery.

Steps

Making an action plan

    Determine the degree of nipple inversion. Take off yours outerwear and stand near the mirror. Holding your breast at the edge of the areola (the dark area surrounding the nipple) with your thumb and forefinger, squeeze about an inch behind the nipple. Act carefully but confidently. Depending on the reaction of the nipple, three degrees of inversion can be distinguished.

    Find out the cause. If you have had nipples like this since childhood or adolescence, then they are unlikely to be a symptom of any disease. The opposite is also true - if the changes have occurred recently, and especially if you are over 50, then illness or infection may be to blame. Cancer and other serious pathologies (infections and inflammatory processes) can cause the development of nipple inversion.

    Decide on a treatment method. Treatment depends on the cause and severity of inverted nipples and whether you plan to breastfeed. If you have symptoms of breast cancer, infection, or blocked milk ducts, contact your doctor immediately.

    • If you have grade 1 nipple inversion, then most likely manual methods can ease fibrosis and allow nipples to protrude normally.
    • If you have grade 2 or 3 nipple inversion, it is best to consult a doctor so that he can create an individual treatment plan for you. In some cases, non-invasive methods can be very effective, in other cases the best solution there will be surgery.
    • If you are pregnant or breastfeeding, consult your doctor or lactation consultant.
  1. Roll your nipple between your thumb and index finger several times a day. Gently pull on the nipple and roll it between your fingers, causing it to stay out longer. Then wet a towel with cold water and rub it over your nipples to keep them erect.

Use of special means

    Buy breast cups. They are sold in maternity stores and online. Breast cups are soft, slightly convex discs with a small hole in the center that pushes the nipple forward.

    Use a breast pump. If you are pregnant or breastfeeding, use this nipple traction device.

    Use an inverted syringe. Draw out the nipple using a clean syringe with a capacity of about 10 ml (the size of the syringe may vary depending on the size of the nipple).

    • Using clean, sharp scissors, cut off the tip of the syringe where the “0 ml” mark is (on the side opposite the plunger).
    • Remove the plunger and reinsert it on the side where you just cut. Push the plunger down until it goes all the way.
    • Place the uncut end over the nipple and pull the plunger out until the nipple protrudes.
    • If you feel discomfort, do not pull the plunger any further.
    • Before removing the syringe, apply slight pressure to the plunger to release the pressure.
    • After completing the procedure, rinse all parts of the syringe in hot water with soap.
    • You can also purchase a special medical device called Evert-It. It is a similar slightly modified syringe and works on the same principle.
  1. Use Niplette corrector. The Niplette corrector is a device that lengthens the milk ducts, stretching the nipple for a long time. This is a small transparent nipple cap that is worn under clothing.

  2. Use Supple Cups concealer. Supple Cups, sold online, will help people suffering from nipple inversion by “pulling” them into a special cup. According to the results of clinical studies, complete disappearance of the problem was achieved in just a few weeks.

    • Place the Supple Cup on the nipple, then gently squeeze the bottom of the cap, pressing it gently against the nipple. This will create a vacuum, which will pull out the nipple.
    • It will be better if you use a small amount of nipple cream or oil. Apply cream or oil to the nipple and the inside of the Supple Cup. If that doesn't work, you may need to try a different size cap.
    • On the first day, you should wear the Supple Cups for 15 minutes. If this does not cause you pain or discomfort, then you can increase the time you wear the corrector, reaching 4 hours per day by the end of the first week.
    • Someone can wear this corrector under their bra without experiencing discomfort or creasing the caps. However, you can use Breast Shells together with Supple Cups to avoid the cap being crushed by a tight bra, too much pressure, or the cap being pulled away from the nipple.