Dysmenorrhea can be literally translated as "difficult monthly flow." Although it's normal for most women to have mild abdominal cramps on the first day or two of their period, about 10% of women experience severe pain.
There are two types of dysmenorrhea:
Primary dysmenorrhea is thought to be caused by excessive levels of prostaglandins, hormones that make your uterus contract during menstruation and childbirth. Its pain probably results from contractions of your uterus that occur when the blood supply to its lining (endometrium) is reduced.
Usually, the pain will happen only during menstrual cycles in which an egg is released. The pain may progressively become worse as endometrial tissue shed during a menstrual period passes through the cervix, particularly when the cervical canal is narrow.
Other factors that may make the pain of primary dysmenorrhea even worse include a uterus that tilts backward (retroverted uterus) instead of forward, lack of exercise, and psychological or social stress.
Secondary dysmenorrhea may be caused by a number of conditions, including:
The main symptom of dysmenorrhea is pain. It occurs in your lower abdomen during menstruation and may also be felt in your hips, lower back, or thighs. Other symptoms may include nausea, vomiting, diarrhea, lightheadedness, or general achiness.
For most women, the pain usually starts shortly before or during their menstrual period, peaks after 24 hours, and subsides after 2 to 3 days. Sometimes clots or pieces of bloody tissue from the lining of the uterus are expelled from the uterus, causing pain.
Dysmenorrhea pain may be spasmodic (sharp pelvic cramps at the start of menstrual flow) or congestive (deep, dull ache). The symptoms of secondary dysmenorrhea often start sooner in the menstrual cycle than those of primary dysmenorrhea, and usually last longer.