A light period or a period that stops before you expect may happen for a variety of reasons. Weight, age, or changes in medication can impact your period. Spotting or a missed period may indicate an underlying medical condition or pregnancy.

Understanding what’s “normal” for a period will help you determine whether your period is, in fact, light. A period comes when the lining of your uterus sheds through your cervix and vagina, generally on a monthly basis.

Your period is generally consistent in number of days and the level of flow. Women typically get their period every 21 to 35 days. Menstrual flow can range between two and seven days. However, your period can change over time and because of different circumstances. For example, if you are pregnant, you will not experience a period because the lining will not detach.

Every woman and period is different, so your period may come like clockwork or be more unpredictable.

You may be concerned about a light period if:

  • you bleed for fewer than two days
  • your bleeding is very light, like spotting
  • you miss one or more regular-flow periods
  • you experience more frequent light periods than the typical 21- to 35-day cycle

Remember that you may experience an unusual period for no particular reason, but you should still let your doctor know. They can help determine any underlying causes that may be affecting your menstrual cycle and vaginal bleeding.

Light periods can be the result of a variety of causes. These include:


Your period can vary in length and flow if you are in your teenage years. On the flip side, if you are in menopause, you may experience irregular periods that are light in flow. These occurrences are the result of hormonal imbalances.

Weight and diet

Body weight and body fat percentage can affect your period. Being extremely underweight can cause your period to become irregular because your hormones are not working normally. Additionally, losing or gaining an extreme amount of weight can cause irregularities with your period.


If you are pregnant, it is unlikely that you will have a period. You may notice some spotting and think it’s your period, but it may actually be implantation bleeding. This can occur when a fertilized egg attaches to the lining of the uterus. Implantation bleeding usually lasts for two days or less.

Learn more: Early pregnancy symptoms no one tells you about »


If you are breast-feeding, your periods may not come back immediately after you give birth. The milk production hormone prevents ovulation and delays your period from returning. You may get your period months after giving birth if you are breast-feeding.

You can still get pregnant while breast-feeding, even if your period has not yet returned. That’s because you will ovulate two weeks before your first post-natal period. If you’ve had unprotected sex while breast-feeding and are experiencing spotting, it’s a good idea to take a pregnancy test to confirm that the spotting was not caused by implantation bleeding.

Birth control

Hormonal birth control may be the cause of a light period. Some birth control methods prevent an egg from releasing in your body. These methods come in various forms, including:

When your body doesn’t release an egg, your uterus doesn’t create a thick lining. This can result in lighter periods or skipped periods altogether.

You may also experience irregular periods if you have started or stopped taking birth control recently.


If you’re stressed, your brain can alter the menstrual cycle hormones. You may experience skipped or lighter periods because of it. Once a stressful event passes, your periods should return to normal.


Women who exercise frequently may experience changes to their period. Athletes can be under stress, have low body weight, and use a lot of body energy. This can result in altered periods.

Eating disorders

Anorexia nervosa and bulimia are types of eating disorders that may cause irregular periods. Eating disorders can lead to low body weight, which can alter hormones that regulate your period.

Polycystic ovary syndrome (PCOS)

If you’re experiencing irregular periods or have stopped menstruating, it could be the result of PCOS. This causes a hormonal change in your body where your eggs stop maturing.

This hormonal change may also:

Your doctor can diagnose PCOS through the use of an ultrasound. That’s because PCOS causes cysts to form in your ovaries. If you have PCOS, your doctor will likely recommend that you lose weight and take contraceptive pills to help your period return to normal. Your doctor may also prescribe metformin (Glumetza, Riomet, Glucophage). This medication is usually prescribed for people with type 2 diabetes, but it is sometimes used off-label to treat people with PCOS. It helps control insulin levels and may help to improve ovulation, which can regulate your menstrual cycle.

What is off-label drug use?

Off-label drug use means that a drug that’s been approved by the FDA for one purpose is used for a different purpose that has not been approved. However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs, but not how doctors use drugs to treat their patients. So, your doctor can prescribe a drug however they think is best for your care.

Learn more: Off-label prescription drug use: What you need to know »

Serious medical conditions

Unusual or irregular periods may be a sign of a more serious health condition. Regular periods indicate that your body is in good working order. A light period could be a sign of problems with hormone levels or another medical condition. Polycystic ovary syndrome and issues with reproductive organs can lead to irregular periods.

Discussing symptoms with your doctor may help you determine the cause of lighter than normal periods.

Women of any age can be at risk for light periods. A light period can be a sign that your body is not working as it should. You should talk to your doctor about what might be causing it.

Women who experience no period for three months or longer may be diagnosed with amenorrhea.

Read more: Menstrual problems »

Your period may be lighter than usual with no underlying cause. Contact your doctor if you:

Additionally, contact your doctor if you notice any other concerning symptoms.

Your light period may be caused by one of many factors. It may be a one-time occurrence. If your light periods persist or you experience any troubling symptoms, you may need further treatment.

Your doctor will discuss possible reasons for your light periods and test you for various conditions to determine an appropriate treatment plan.

Persistent and problematic light periods may be treated with changes to your lifestyle and medications. Sometimes, the use of hormonal birth control can help your periods become more regular. If your light periods are a sign of something more serious, treatment may include other medications or other interventions.

Light periods may not be a sign that you have something to worry about. Even a period as short as two to three days is considered normal. If you have missed a period or experienced light spotting and think you might be pregnant, take a pregnancy test. Make sure to track your light periods and talk to your doctor.