During a period, the uterus sheds its lining, causing blood and tissue to exit through the v*gina.

The amount of blood and tissue can vary from day to day, but the period typically stops around 2–7 days after it starts.

Occasionally, a period may take longer than usual to stop. There are several potential reasons for this, including the use of birth control and the presence of underlying health issues. In this article, we cover 10 potential reasons why a period may not stop.

1. Ovulation

Some people experience bleeding during ovulation, which is when the ovaries release an egg. In most cases, ovulation will produce only slight spotting and is not a major cause for concern. When it occurs toward the end of a period, spotting from ovulation can make it seem as though the period is lasting for longer than usual.

2. Intrauterine devices

A healthcare professional can insert an intrauterine device (IUD) into the uterus to help prevent pregnancy. The two main types of IUD, hormonal and nonhormonal, can both cause abnormal bleeding. Heavy and irregular periods are particularly common when a person first receives the IUD. However, in most cases, heavy or prolonged bleeding should go away after 3–6 months.

3. Hormonal birth control

Hormonal birth control pills alter the body’s natural hormone levels. Although many people use hormonal contraceptives to shorten or regulate their periods, they can sometimes result in heavier or prolonged periods. Abnormal periods are common during the first few months of taking a new hormonal medication. However, if they continue to occur after several months or become bothersome, speak to a doctor about switching birth control methods.

4. Thyroid problems

The thyroid gland is responsible for regulating a variety of hormones in the body. For females, this includes hormones associated with the menstrual cycle. If a person has an underactive or overactive thyroid, they may experience long periods or ones that seem as though they will not stop. Thyroid problems can also cause very light periods, several months without a period, and early menopause.

5. Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) occurs when cysts frequently grow on the ovaries. PCOS can affect hormone levels and fertility. Symptoms of PCOS include: Irregular period, excess hair, weight gain, thinning hair on the head, acne, skin tags, and darkening of the skin around the neck, groin, and breasts.

6. Uterine fibroids or polyps

Fibroids are muscular, usually benign tumors that form on the wall of the uterus. Polyps are red growths on the lining of the uterus. Both are common problems that can cause heavier or longer-than-normal periods to occur.

7. Pregnancy loss

Pregnancy loss, or miscarriage, often causes bleeding or spotting. This bleeding can be light or heavy and may last anywhere from a few hours to a few weeks. In some cases, pregnancy loss can occur before a woman realizes they are pregnant. If a miscarriage is responsible for the bleeding, it is best to speak to a doctor to ensure there are no complications.

8. Pregnancy

Some women experience spotting or light bleeding in early pregnancy. Bleeding may occur with or without other signs of pregnancy, such as nausea. Abnormal bleeding and pelvic pain during pregnancy may be a sign of an ectopic pregnancy, which can cause serious complications.

9. Blood disorders

Though uncommon, it is possible that someone experiencing a prolonged period may have an underlying blood disorder. The most common blood disorder in females is von Willebrand’s disease. Blood disorders can cause heavy bleeding and periods that last for longer than 7 days. Other symptoms of a blood disorder include: anemia, heavy bleeding after surgery and childbirth, bleeding for more than 10 minutes during a nosebleed, bleeding for longer than 5 minutes after a cut ,and easy and frequent bruising
Endometriosis is a condition in which tissue that is similar to the tissue that lines the uterus grows outside of the uterus. This tissue can swell and bleed in response to hormones, just as the uterine lining does during a period. Endometriosis lesions cannot exit the body, however, so they may result in pain and other complications, such as adhesions and cysts. Symptoms of endometriosis can include:
  • painful menstruation
  • chronic pain in the back and pelvis
  • pain during sex
  • bleeding between periods
  • painful bowel movements
  • stomach problems, such as nausea, constipation, and bloating
  • infertility