A black or very dark period with thick blood can result from slower uterine shedding or prolonged exposure to air. This often occurs at the start or end of menstruation. However, unusually thick or consistently dark blood may indicate underlying conditions.
Menstrual blood typically appears bright red when freshly shed. As it leaves the uterus and travels through the vagina, exposure to oxygen causes it to darken. Older blood or blood that has been in the uterus longer may appear brown or black.
Several factors can contribute to darker, thicker menstrual blood:
Consult a healthcare provider if you experience any of the following alongside dark, thick menstrual blood:
Your doctor will likely ask about your medical history and symptoms. They may perform a pelvic exam or order tests such as:
Treatment options depend on the underlying cause and may include medication, lifestyle changes, or surgical interventions.
I noticed my period becoming darker and thicker after switching to a hormonal IUD. While my doctor assured me this was normal, they recommended tracking my cycles to ensure consistency. After a few months, my period returned to its usual color and texture, confirming the changes were temporary.