While brown discharge can be a period-related sign, it can also be caused by other hormonal changes and conditions affecting the uterus and ovaries.

When blood leaves the body quickly, it’s usually a shade of red. But if the flow slows, the blood has time to oxidize and turn brown. Sometimes, this may indicate an underlying condition, like a hormonal imbalance or infection.

Other symptoms, such as a strong smell, can indicate an underlying condition.

Your menstrual flow is generally slower at the beginning and end of your period.

When blood leaves the body quickly, it’s usually a shade of red. When the flow slows, the blood has time to oxidize, causing it to turn brown.

You may even notice black discharge if your period is particularly heavy.

Other times, brown discharge may signal a hormonal imbalance.

Estrogen helps stabilize the endometrial (uterine) lining. If too little estrogen circulates, the lining may break down at different points throughout your cycle.

As a result, you may experience brown spotting or other unusual bleeding. Low estrogen may also lead to:

  • tender breasts
  • difficulty concentrating
  • mood changes
  • vaginal dryness
  • hot flashes
  • night sweats
  • insomnia

A healthcare professional will be able to advise on treatment, which usually comes in the form of hormone therapy.

Hormonal contraception, like birth control pills and IUDs, may lead to spotting in the first months of use as your body adjusts to the hormonal changes.

Breakthrough bleeding is more common if your contraceptive contains little to no estrogen.

If there’s too little estrogen in your body, your uterine wall may shed its lining between periods. And if this lining takes a while to leave the body, it may appear brown.

If your spotting continues for more than 3 months, consider talking with a healthcare professional about changing birth control methods. A contraceptive with more estrogen may help stop the spotting.

Similarly, if you forget to take your pill for a few days, you may experience temporary spotting.

A small number of people — around 3% of participants in a 2012 study — experience ovulation spotting at the midpoint of their menstrual cycles. This is when an egg is released from the ovaries.

Estrogen levels are high at this point and subsequently drop, which can trigger spotting. The color may range from red to pink to brown and may also be mixed with clear discharge.

Other symptoms of ovulation include:

Ovarian cysts are fluid-filled pockets or sacs that develop in or on an ovary.

These generally aren’t a cause for concern. A functional cyst, for example, can develop when the follicle that released an egg doesn’t shrink back to size after ovulation or when an egg fails to release. It may not cause any symptoms and go away on its own after a few months.

Sometimes, the cyst doesn’t resolve and may grow larger. If this happens, it may cause anything from brown spotting to feelings of pain or heaviness in your pelvis.

Other cysts include endometriomas (also known as chocolate cysts), which contain old tissue and blood. Dermoid cysts form from ovarian cells and eggs and may be filled with skin, teeth, hair, or fat.

Cysts of any type that continue to grow risk rupturing or twisting the ovary.

If you think you may have a cyst, consult a healthcare professional. If they find a cyst, they may ask to see you again in a few months to check that it’s gotten smaller.

Sometimes, they might recommend birth control pills to prevent ovulation and more cysts from forming. In some cases, you may need surgery — particularly if the cyst continues to grow, causes continual discomfort, or might be cancerous.

Some sexually transmitted infections (STIs), such as gonorrhea or chlamydia, may not cause symptoms in the early stages.

In time, possible symptoms include pain with urination, pelvic pressure, spotting between periods, or vaginal discharge that’s different in color or smell from your usual discharge.

Bacterial vaginosis (BV) is caused by an overgrowth of bacteria that can change your discharge’s texture, color, or smell. Some people notice discharge with a fishy smell that looks thin and gray, while others have no symptoms.

Talking with a healthcare professional if you suspect you have an STI or other infection is important. They will diagnose the specific infection and prescribe antibiotics or antifungal medication.

STIs that are left untreated can cause pelvic inflammatory disease (PID). Heavy brown discharge with a strong smell may be seen along with pelvic pain, discomfort during sex, and pain when urinating.

PID can affect fertility and lead to chronic pain, but it typically responds well to antibiotics.

Endometriosis occurs when uterine-like tissue grows elsewhere in the body. When it sheds, it’s unable to exit the body. This may cause severe pain and brown discharge.

Other symptoms include:

  • back pain
  • pain during penetrative sex
  • spotting between periods
  • painful bowel movements
  • constipation
  • nausea

Endometriosis is a chronic condition without a cure. But you can manage symptoms with medication, hormone therapy, or surgery to remove areas of tissue.

PCOS is a hormonal disorder that’s often characterized by menstrual irregularities.

You might experience irregular or infrequent menstrual periods, with more than 35 days between each period. This extended time between periods can result in brown discharge.

Other symptoms include:

PCOS is usually managed with medication, including birth control pills, to regulate your menstrual cycle.

Implantation occurs when a fertilized egg embeds itself into your uterine lining.

It happens around 1 to 2 weeks after fertilization and may cause light bleeding of various shades, including brown.

Other early pregnancy symptoms may include:

  • cramping
  • fatigue
  • nausea
  • tender breasts
  • frequent urination
  • bloating

Consider taking a home pregnancy test if your period is late or you’re experiencing brown spotting in its place.

If you receive a positive test result, make an appointment with a healthcare professional to confirm your results and discuss your options.

Sometimes, a fertilized egg may implant itself into the fallopian tubes or in the ovary, abdomen, or cervix. This is called an ectopic pregnancy.

In addition to brown spotting, ectopic pregnancy may cause:

  • low back pain
  • pain on one side of your abdomen
  • pain in your shoulder
  • weakness
  • dizziness
  • fainting

If you suspect an ectopic pregnancy, seek immediate medical care.

Treatment involves removing the tissue, either with medication or surgery. Without treatment, an ectopic pregnancy can cause your fallopian tube to burst. A ruptured fallopian tube can be life threatening.

Bleeding in early pregnancy isn’t always a cause for concern. But it’s important to report brown discharge or other unusual symptoms to your care team.

Symptoms may come on suddenly and include a gush of brown fluid or heavy red bleeding.

Other symptoms include:

  • passing large blood clots or tissue
  • pain on one side of your abdomen
  • pain in your shoulder
  • diarrhea
  • vomiting

If you think you’re having a miscarriage, seek immediate medical care.

Lochia, or postpartum discharge and bleeding, can last up to 6 weeks after a miscarriage or birth.

It begins as a heavy red flow. After a few days, the bleeding typically slows and may become browner in color. This discharge changes yet again after around 10 days to more of a yellow or creamy color before it trails off completely.

See a healthcare professional if you develop strong-smelling discharge, stomach pain, or a fever. These signs, along with passing large clots, could be signs of infection.

You reach menopause after you experience 12 consecutive months without a menstrual period. The time before this stage is known as perimenopause. Perimenopause typically begins in your late 40s.

Fluctuating estrogen levels during this period can cause irregular bleeding or spotting, which may be brown, pink, or red in color.

Other symptoms include:

If you think you’re in perimenopause, consult with a healthcare professional. They can perform a blood test to make or confirm a diagnosis. They can also prescribe medication to help manage your symptoms during this transition.

In many cases, brown discharge is simply old blood that’s taking extra time to leave the uterus. This is especially true if you see it at the beginning or end of your menstrual period.

Brown discharge at other points in your cycle may still be nothing to worry about — but note when it happens, what it looks like, and any other symptoms you experience so a doctor can help pinpoint the underlying cause.

They’ll most likely perform a pelvic exam and may need to swab the discharge for testing.