Dysmenorrhea is also known as painful menstruation or periods, or menstrual cramps, pain during menstruation. There are two types of dysmenorrhea: "primary" and "secondary".

Primary dysmenorrhea is the most common kind of dysmenorrhea. Cramping pain in the lower abdomen (belly) can start from 1–2 days before your period begins and can last 2–4 days.

Pain can range from mild to severe and can be accompanied by nausea-and-vomiting, fatigue, and even diarrhea. There is no associated pelvic disease. 

Primary dysmenorrhea is thought to be caused by excessive levels of prostaglandins. The pain subsides on its own once the woman gets pregnant or after delivery. Family history such as mother or sister having similar complaint may be present. 

Secondary dysmenorrhea is pain that is caused by a disorder in the woman's reproductive organs, such as endometriosis, adenomyosis, uterine fibroids, or infection, placement of copper-T. Pain from secondary dysmenorrhea usually begins earlier in the menstrual cycle and lasts longer than common menstrual cramps. 

Endometriosis – this is caused by the cells lining the womb growing in the fallopian tubes or ovaries.  When these cells shed and fall away they cause intense pain. 

Adenomyosis – Adenomyosis is a condition in which the cells that line the inside of the uterus (endometrium) are abnormally located in cells that make up the uterine wall (myometrium). This can result in a somewhat enlarged uterus. Adenomyosis can cause very painful menstruation or periods and heavy bleeding. 

Pelvic inflammatory disease – the womb, fallopian tubes and ovaries become infected with a bacteria which leads to inflammation.  Other symptoms include fever and vaginal discharge.