Many believe women bleeding out of their vaginas is a once-a-month thing. But bleeding between menstrual cycles, defined as spotting, is a common occurence that could have myriad explanations, from mild to severe.

“It is considered abnormal because it is a symptom of an underlying problem, but it is not a rare occurrence. Nine out 10 women will have experienced spotting at some point,” Dr. Komal Sahay, a gynecologist at Mumbai’s Mamta Maternity Home, says.

Sometimes, spotting occurs before or after women get their period, which makes it hard to determine the difference between spotting and the main event, Dr. Sahay says. “The only way to know the difference is to keep a track of the cycle to see if it begins or ends with what we think is a normal flow. If the cycle begins with light, irregular bleeding, or once it has ended and you experience the same, then you might be spotting,” she says.

While keeping in mind that every woman’s spotting pattern may be different, Medical News Today (MNT) describes its characteristics as having irregular timings, and advises women to see if the blood is a different color fromthat of menstrual blood. “Some women spot brown blood, for others, it may be lighter, of a different texture orit may smell odd,” MNT describes.

Here is the list of causes women may bleed between cycles:

Hormonal imbalance

The two hormones, estrogen and progesterone, that regulate your cycle can get out of balance due to various reasons, such as starting or stopping birth control pills, having dysfunctional ovaries or problems in the thyroid gland.

“Spotting is common in the first four or five months of starting or after stopping birth control pills,” says Dr. Sahay. “It just means that the body is getting used to hormones present in the pills. However, if you continue to spot for a duration longer than that, or if you observe that your spotting has begun only a few months after the use or discontinuation of pills rather than immediately, then it could be due to its side-effects or might be pointing towards another problem,” she adds.

Hormonal shifts caused by breastfeeding may also result in spotting, she says.

Pregnancy-related complications

A week after the zygote implants itself in the uterus (post fertilization of the sperm and egg after sex), spotting or some light bleeding can occur. But, if you’re pregnant and experience any vaginal bleeding after the implantation phase, you need to get in touch with a doctor immediately because you might be having a miscarriage or an ectopic pregnancy (where the fertilized egg implants itself in the fallopian tube instead of the uterus), Dr. Sahay says.

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Infections

Spotting could also be a symptom of infections of the reproductive organs.

Some sexually transmitted infections like gonorrhea, that are accompanied by pain and can last several months, may end up causing an unusual discharge or result in spotting.

Pelvic inflammatory disorders or PID, i.e., the inflammation of the reproductive organs (uterus, fallopian tubes, ovaries) is caused primarily by STIs that spread up from the opening of the uterus to these organs. Along with an abnormal or foul discharge from the vagina or urethra, PID can also cause pain or bleeding during or after intercourse or penetration, or irregular bleeding or spotting.

Inflammation of the cervix, or cervicitis, may also be another cause of spotting. It is caused due to an STI or because of allergies, irritation or injuries to the cells that line the cervix that may lead to spotting.

“In some cases, spotting after sex may just be because of friction or the absence of enough lubrication during sex,” says Dr. Sahay.

Uterine polyps and fibroids

Uterine polyps are growths attached to the inner walls of the uterus that extend into the uterine cavity. They are usually benign or noncancerous growths, but they can turn malignant or cancerous. Irregular menstrual bleeding — for instance, bleeding frequently or experiencing unpredictable periods of variable lengths and flow, or bleeding between cycles — are usually the condition’s biggest symptoms.

Fibroids are another reason why women might experience spotting. While polyps happen around menopause, fibroids develop in the reproductive years. They are abnormal growths of the muscle tissue that form on the walls of the uterus and like polyps, have the same symptoms — irregular menstrual bleeding or spotting.

Cancer

Ovarian, vaginal, uterine or cervical cancer can cause abnormal bleeding from the vagina too, says Dr. Sahay.

“Spotting is often accompanied by pain and other symptoms and can last several months. Symptoms may get better and then worse, or get progressively worse,” according to MNT. “Women who are past menopause or who have a family history of these cancers are at a heightened risk,” it adds. So, if postmenopausal women experience vaginal bleeding, it is not normal and it needs immediate attention, Dr. Sahay says. “For women who are still menstruating but experience spotting frequently, unless there is a check-up, it could be said to be a symptom of any of the above including any form of cancer. Hence, it is important that women keep a track of their cycle, assess if they’re spotting and get it checked immediately.”

In many cases, abnormal bleeding will subside on its own. But if it doesn’t, you should seek medical attention.

“There is no specific treatment for abnormal bleeding unless we know about the problem that is causing it, for which there are treatments available and can be administered only once the tests, scans and their results confirm their presence,” says Dr. Sahay. “But one can consider preventive measures too. After a check-up, a doctor may recommend maintaining a healthy lifestyle or including more physical activities that if followed can keep the stress levels in check, in turn, maintaining a balance in hormones that regulate the cycle.”