Watery Period: What Does Thin or Light Period Mean?

Watery Period: What Does Thin or Light Period Mean?

Many women become worried and concerned if they start having a watery period. Watery period blood has a lighter consistency and color than what some women experience during their normal period. Although for many women a lighter blood flow sounds like a good thing, a light watery period could indicate that there are some health issues affecting the menstrual blood.

If you have a watery light period, it could be caused by hormonal fluctuations, stress, or using birth control. In some cases, a light irregular period could be the result of polycystic ovary syndrome or an eating disorder. Of course, each woman’s menstrual cycle is different, and for some women a light watery period is normal.

In this article, you will find out what it can mean if your menstrual period blood appears to be light and watery. You will also find out, in some cases, what you can do to if you have started having watery periods and when you should speak to a doctor about it.

What is a Watery Period or Light Period?

Watery (light) period describes menstrual period blood that has a thin consistency that looks watery. Some describe this as a light period and the menstrual blood will often have a lighter pink color rather than dark red blood.

According to the book Clinical Methods in the chapter “Abnormal Vaginal Bleeding,” hypomenorrhea is a medical term that describes short, light period. This type of light period flow is usually less than 30 ml during the menstrual period.1 Because the low amount of blood mixes with regular vaginal discharge, it can look watery with a thin consistency.

Another reason for a watery period could be due to having infrequent menstrual periods. The medical term of for this is oligomenorrhea (infrequent menstrual periods). According to the University of Maryland, oligomenorrhea can cause light menstrual periods or infrequent menstruation.2  

Causes of a Watery Period (Light Thin Period)

Let’s look in more detail at the various causes of experiencing light or watery periods during menstruation.

Light period flow

Some women naturally have a light period flow and for them, a watery period can be normal.

According to doctors from the Mayo Clinic, the amount and consistency of the menstrual flow can differ from woman to woman. The menstrual cycle starts on the first day of your period and the menstrual flow occurs every 21 to 35 days. Your period may be light or heavy and may last between 2 and 7 days.3

So how do you know if a watery period is normal for you? Doctors recommend keeping a menstrual diary to track your periods. This should include the type and consistency of flow as well as the length of your menstrual cycle. Keeping a menstrual diary can help you spot any irregularities and help you spot times when your period is more watery or lighter than normal.

Light period and pregnancy

In some cases, what you think is a watery period may, in fact, be implantation bleeding and a sign that you are pregnant.

Implantation bleeding or light spotting can happen when a fertilized egg implants into the lining of your uterus. This can cause spotting and mild cramping which may be mistaken for the start of your menstrual period.

Dr. Nivin Todd, who is one of the leading obstetrics and gynecologists in the U.S., says that implantation spotting happens about 6 to 12 days after conception. The light bleeding looks like light period blood that is pink in color and is just a light flow. Implantation bleeding only lasts a few days. This usually happens around the time when you are expecting your period.4

Dr. Todd says that light spotting in very early pregnancy is nothing to worry about. However, if you experience heavy vaginal bleeding along with bad abdominal pain, you should speak to your doctor as soon as possible.

Watery period with cramps because of hormone fluctuations

Ups and downs in your hormone levels can also cause you to have a watery period from time to time.

Professor Jennifer Knudston, who is an expert in obstetrics and gynecology at the University of Texas Health Center, says that the menstrual cycle is regulated by hormones. The complex interaction of your body’s hormones regulates ovulation, menstrual flow and consistency, and when the period starts. For some women, fluctuations in hormone levels can mean a lighter period or heavier period.5

Light, watery periods are just one of the signs that you could have a hormonal imbalance. There are natural ways to get your hormones back in balance and regulate your menstrual cycle. For example, you can try increasing your intake of foods that balance your hormones. This can help to increase your levels of progesterone and make your periods more regular.

Stress and watery period

Stress can be a reason for abnormal menstruation with watery periods that are light and irregular.

According to doctors from the Cleveland Clinic, abnormal periods are when your menstrual flow is lighter or heavier than usual. You may also miss periods or have periods that last longer than seven days. Stress is a common reason for problems with your menstrual cycle.6

Stress and lifestyle factors can greatly affect your periods. Doctors from the National Health Service (NHS) report that disruptions to your daily routine or increased anxiety can cause irregular periods. If you are stressed out, your periods may become shorter and lighter. In fact, they may stop altogether if you are under extreme stress.7

If you feel that stress is causing your periods to be watery and possibly infrequent, you can try some natural stress relief remedies. For example, many essential oils can help release stress and tension. Some of the best essential oils to use if you are stressed are lavender, bergamot essential oil, chamomile, and geranium.

Birth control with light watery period

You may start having a light watery period if you have recently started using a birth control pill.

According to the University of Iowa, birth control pills can help regulate your menstruation and will result in lighter periods.8 Doctors from the NHS say that small light bleeds are common when first using oral contraceptives.9

Another form of contraceptive that can make your periods lighter is an intrauterine device (IUD). Dr. Traci Johnson from WebMD says that an IUD can make women have light periods.10

If you are concerned about vaginal bleeding while using hormonal contraception, you should speak to your doctor.

Watery period during perimenopause

As you approach the menopause, you might find that you start having more frequent watery light periods.

The perimenopause stage is the few years before the menopause when you start noticing irregularities in your menstrual cycle. According to doctors from Harvard Health, you might start experiencing lighter periods for several months before your period stops completely.11

The American Congress of Obstetricians and Gynecologists reports that you may also experience heavier and longer menstrual periods during the perimenopause. However, if you have heavy bleeding and bleeding between periods, you should speak to your doctor.12

If you are postmenopausal and notice any spotting or signs of vaginal bleeding, you should speak to your doctor.

Going through this change puts a lot of stress on your body because of changing hormone levels. You can try some natural herbs to support you through the menopause. Also, many women have found that essentials oils like peppermint oil, lavender essential oil, and sweet marjoram provide natural relief from menopause symptoms.


You might find that as your periods resume while breastfeeding, your first few periods are watery and lighter than what you were used to.

Health advice from the Australian Government says that there are a few factors that determine when periods return while breastfeeding. For example, how often you bottle feed, hormonal changes, and how long you breastfeed affect when your period returns. At the start, your periods will be light and you might notice some light spotting.13

Polycystic ovary syndrome and watery periods

Problems with your ovaries may cause you to have irregular periods with light, watery period blood.

One such problem that can affect your menstrual cycle is polycystic ovary syndrome (PCOS). Dr. Mary Harding on Patient.info explains that PCOS is a condition where tiny cysts grow on your ovaries and alter the balance of hormones in your body. One of the symptoms of PCOS is having irregular or very light periods.14

According to Dr. Harding, one of the best ways to treat polycystic ovary syndrome naturally is to lose weight and reduce insulin levels in the body. This acts to reduce levels of the male hormone testosterone which is usually elevated in women with PCOS.

Eating disorders affect period flow and consistency

Various eating disorders can affect your menstrual cycle and interfere with menstrual flow and consistency resulting in thin light periods.

Various scientific studies have pointed to the relationship between eating disorders and menstrual abnormalities. For example, the journal Psychosomatic Medicine reported that eating disorders like anorexia nervosa and bulimia can result in menstrual dysfunction.15

Also, a report in the Journal of Psychosomatic Research found that binge eating can also cause issues with menstrual periods. It was found that around 50% of women with bulimia nervosa suffer from oligomenorrhea (infrequent and watery period).16

When to See a Doctor for Watery Period

In most cases, if you have an occasional watery period or if you normally have light periods, there is nothing to worry about. Usually, when the underlying health issue like stress or fluctuations in hormone levels get sorted, your menstruation should return to normal.

However, in some cases, it’s important to speak with your doctor about menstrual abnormalities. According to Dr. Mikio Nihira on WebMD, every woman should track their own menstrual cycle to see what is normal for them. Changes in your menstruation that may indicate a more serious condition include:17

  • Your period slows down or stops for no apparent reason.
  • You start having periods that are heavier and/or longer than usual.
  • You notice bleeding between periods.
  • During menstruation, you get a lot of abdominal pain and intense cramping.
  • Your period occurs more often than every 21 days or less often than every 35 days.

Article Sources

  1. NCBI. Clinical methods – abnormal vaginal bleeding.
  2. UMM. Menstrual disorders.
  3. MayoClinic. Menstrual cycle: What’s normal and what’s not.
  4. WebMD. What is implantation bleeding?
  5. MSDManuals. Menstrual cycle.
  6. ClevelandClinic. Abnormal menstruation.
  7. NHS. Stopped or missed periods.
  8. UIHC. Birth control fact sheet.
  9. NHS. Irregular periods.
  10. WebMD. Birth control and the IUD.
  11. DrugsCom. Menopause and perimenopause.
  12. ACOG. Perimenopausal bleeding and bleeding after menopause.
  13. Breastfeeding and periods.
  14. PatientInfo. Polycystic ovary syndrome.
  15. Psychosom Med.1989 Jan-Feb;51(1):81-6.
  16. J Psychosom Res. . 2014 Jan; 76(1): 19–22.
  17. WebMD. When your period signals a problem.

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