If your menstrual blood varies in color and consistency throughout your monthly period, it's likely that it's perfectly normal. There are times, though, when changes in color, thickness, or clotting may indicate a problem.
By Amy Engeler
At 3 a.m., with all the houses dark up and down her winding suburban street in West Warwick, Rhode Island, Jo-Ann Frey, 37, lights a candle so she can see well enough to dust her furniture. Careful not to turn on any lights or make noise that might wake up her family, she drifts from room to room with her candle and cleaning supplies, waiting until she feels sleepy enough to climb back into bed. That feeling doesn't come -- and when she hears the alarm in the bedroom go off...
What happens during a menstrual period, and how long does it last?
During your menstrual cycle, the lining of your uterus thickens to get ready for pregnancy. Then, during your period, your body sheds the uterus lining along with blood. The amount of blood and fluid lost is usually between 4 and 12 teaspoons each cycle.
The average menstrual cycle lasts 28 days (counting from the first day of bleeding to the first day of the next cycle). For some women, though, cycles can be as short as 21 days. For others, they can be as long as 35 days.
A normal period lasts between two and seven days. The average length of time for a period is three to five days.
Are clots and thicker menstrual blood unusual during a period?
Many women have clots in their menstrual blood from time to time. The clots may be bright red or dark in color. Often, these clots are shed on the heaviest days of bleeding. The presence of multiple clots in your flow may make your menstrual blood seem thick or denser than usual.
Your body typically releases anticoagulants to keep menstrual blood from clotting as it's being released. But when your period is heavy and blood is being rapidly expelled, there's not enough time for anticoagulants to work. That enables clots to form.
If you have excessive clotting or clots larger than a quarter, you should see your health care provider to rule out any conditions that might be causing an abnormal period.
Are darker colors and thicker flows normal in menstrual blood?
You may notice that your menstrual blood becomes dark brown or almost black as you near the end of your period. This is a normal color change. It happens when the blood is older and not being expelled from the body quickly.
Temporary thick, heavy flow isn't necessarily cause for concern. However, regular heavy periods justify a trip to the doctor to check your blood counts. Many women become accustomed to heavy periods, considering them to be normal. Over time, though, the excess monthly blood loss leads to anemia, potentially causing weakness or fatigue. If you ever feel something's not right with your period, see your health care provider.