For some women, it's normal to have watery period blood. But for others, it might be a sign of something else, like a more significant health issue or early pregnancy. To help clear up the confusion, we spoke to Kelly O. Elmore, MD, MBA, a board-certified OB-GYN, and Tsao-Lin E. Moy, L.Ac., MSOM, a Chinese Medicine and Fertility specialist. They gave us insights into whether watery blood could mean pregnancy or something more serious.
Yes, watery period blood can be a sign of early pregnancy. In some cases, this type of bleeding is called implantation bleeding. It can occur during the first 20 weeks of pregnancy, according to medically reviewed information from the U.S. National Library of Medicine.
The National Health Service (NHS) explains that implantation bleeding usually takes place around the time of an expected period and is the result of a fertilized egg attaching to the uterine wall. This causes women to experience light spotting or bleeding during this period. While implantation bleeding is usually not a cause for concern, Dr. Elmore recommends seeking a urine or blood pregnancy test to confirm a pregnancy.
If you aren't pregnant but are experiencing watery period blood, Dr. Elmore says several reasons can cause it. These may include your actual menstrual cycle, certain medications, or dehydration. "Watery period blood also can result from normal changes, hormones, infection, or fluid in the reproductive organs," she adds. However, low estrogen levels can sometimes cause watery period blood, according to Moy. "When estrogen levels are low, the lining will be thinner, and there may be more watery and scant menstrual flow," she explains.
While it's possible to experience light bleeding early in a pregnancy, implantation bleeding is typically characterized by lighter spotting and is not equivalent to a regular period. Moy also indicates that implantation blood has a different color from regular period blood, being light pinkish brown, causing staining, and occurring intermittently for a day or two.
During a regular period, Dr. Elmore explains that it is expected to have light pink, watery period blood, which can occur at the beginning or end of the period, indicating the start or end of the shedding of the uterus lining. However, if the watery period blood appears abnormal in timing or appearance, or if you are over a certain age and have stopped having menses, she says it is crucial to consult a healthcare professional for further evaluation.
"If it's abnormal in timing or appearance, I recommend checking a pregnancy test, rule out an infection, tumor, or cancer," explains Dr. Elmore. "Also, have your healthcare professional do a thorough history and physical exam to include a pelvic/ speculum exam, a pap smear of indicated, and possibly a biopsy of the cervix and uterus, depending on your age."
According to the NHS, thin period blood can look like implantation bleeding because they both occur when a woman expects her period. However, they're not the same — implantation bleeding is usually light spotting or bleeding. Additionally, Moy suggests that early pregnancy may involve increased mucus discharge due to rising pregnancy hormones. "Other signs of pregnancy instead of a period include breast tenderness and swelling," she says.
Moy also highlights the differences in symptoms between period blood and implantation bleeding. She adds, "With period bleeding, there can be spotting, but then the bleeding will continue, becoming progressively heavier with clots, which are pieces of tissue. Period bleeding is also associated with more intense cramping, breast tenderness that can diminish before bleeding, and there can be loose stools."
Yes, hormonal imbalances can lead to watery period blood. Dr. Elmore suggests that this can happen when these imbalances cause changes in the frequency and timing of your menstrual cycle. "Such changes can occur during the onset of menstruation, at different stages of life due to various stressors, and as the ability to reproduce ends," she says. "Additionally, laboratory-confirmed abnormalities, such as thyroid, estrogen, and progesterone imbalances, can contribute to this condition."
Dr. Elmore suggests consulting an endocrinologist to address hormonal imbalances causing watery period blood. These specialists can treat conditions related to hormone issues and collaborate with you to create a personalized treatment plan. They can also prescribe hormonal birth control to help regulate hormonal imbalances.
If you're wondering if it's normal to have light or heavy period blood during your monthly cycle, Dr. Elmore says it's important to know what's normal for you regarding flow and duration. "Your period should come at the same time every month, last for about the same time, and you should have similar symptoms," explains Dr. Elmore. "But this can change due to your hormones, pregnancy, and age."
However, if your period is much heavier and more watery than usual, and it's not normal for you, Dr. Elmore says it's a good idea to talk to your primary care provider or OBGYN. "If this kind of bleeding happens at a different time than your normal period, continues for more than three months, or if you have pain or an unusual smell, it might be a problem, and you should get it checked," she tells Today's Parent. "If you're pregnant and have watery bleeding, it's also important to call a nurse for advice or see a doctor in a clinic or emergency room, depending on how severe the bleeding is."
Believe it or not, sex can sometimes lead to watery period blood. According to Dr. Elmore, this can depend on whether you had sex during your usual menstrual cycle, the intensity of the sex, or any post-encounter trauma. If you're concerned about your period blood or experience any unusual bleeding after sex, Dr. Elmore advises seeking care from your OB-GYN or gynecologist.
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