Why do blood clots occur during menstruation?

Menstrual clots are normal in many women, especially in the first days of menstruation when there is more bleeding. However, if the clots are of considerable size, frequent or if they are accompanied by symptoms such as heavy bleeding or menstrual pain, a specialist should be consulted.
Egg and sperm donation magazine

Blood Clots During a Period: 7 Causes (& What To Do) - Tua Saúde

Period Blood Clots, What Makes Period Blood Clot?

Heavy menstrual bleeding - Symptoms and causes - Mayo Clinic

Blood clots during pregnancy: Symptoms and prevention

Is it Normal to have Blood Clots during Menstruation?

Why do I have blood clots in periods? - Period Blood Clots

Blood clots during your period: what heavy bleeding and jelly like blood clots mean

How to Prevent Large Blood Clots During Menstruation: 12 Steps

Is It Normal for Period Blood to Come Out in Clumps? (for Teens)

Period Blood Color Chart: Decoding Menstrual Health

This is why you get clots in your period blood - and when you should probably talk to a doctor about it

Menstrual clots may cause painful cramps