What causes heavy menstrual bleeding with blood clots?

Apr 01, 2025 Source: Cainiu Health
Disease description:

My menstrual cycles have been somewhat irregular over the past two months, with significantly heavier bleeding and blood clots. However, I haven't experienced any other discomfort. What could be causing this?

Doctor's answer (1)
Dr. Zhang Lu

Heavy menstrual bleeding accompanied by blood clots may be caused by factors such as cold exposure, hormonal imbalances, intrauterine devices, adenomyosis, or endometriosis.

Cold exposure is a common cause. During menstruation, women's bodies are more vulnerable. If proper warmth is not maintained or cold foods are consumed, it may lead to abdominal chilling, resulting in heavy menstrual flow and increased blood clots. Hormonal imbalances, such as inadequate luteal function or thyroid dysfunction, can also disrupt the normal metabolism of the endometrium and lead to similar symptoms.

Use of an intrauterine device can sometimes increase menstrual flow and blood clots. Additionally, blood disorders such as coagulation dysfunction, or chronic liver and kidney diseases may also cause heavy menstrual bleeding with clots. Gynecological conditions like uterine fibroids and adenomyosis can also lead to heavy menstrual bleeding and blood clots. These conditions affect the contractility and surface area of the endometrium, leading to increased menstrual flow and clot formation.

If heavy menstrual bleeding with significant blood clots persists for a prolonged period, it is advisable to seek timely medical attention for targeted examination and treatment.