What exactly causes menstrual cramps?
Answers: Its the muscles around your womb tensing trying to release the blood so you can have your period. The muscles contract and depending on your body you feel them or you don't!
Hope that helps!
Each month, the inner lining of the uterus (the endometrium) builds up in preparation for a possible pregnancy. After ovulation, if the egg is not fertilized by a sperm, no pregnancy will result and the current lining of the uterus is no longer needed. The woman's estrogen and progesterone hormone levels decline, and the lining of the uterus becomes swollen and dies. It is then shed and will be replaced by a new lining in the next monthly cycle.
When the old uterine lining begins to break down, molecular compounds called prostaglandins are released. These compounds cause the muscles of the uterus to contract. When the uterine muscles contract, they constrict the blood supply (vasoconstriction) to the endometrium. This contraction blocks the delivery of oxygen to the tissue of the endometrium which, in turn, breaks down and dies. After the death of this tissue, the uterine contractions literally squeeze the old endometrial tissue through the cervix and out of the body by way of the vagina. Other substances known as leukotrienes, which are chemicals that play a role in the inflammatory response, are also elevated at this time and may be related to the development of menstrual cramps. .
Menstrual cramps are caused by the uterus contracting. It happens on a regular basis, but during PMS it's much stronger. A hormonal substance is released that is involved in the inflammation process. It works to stimulate the muscular contractions that are necessary to shed the lining of the uterus, which causes you to bleed. Some girls have very bad cramps while others are very light. Cramps also act as a way to let you know that you're having your period. Each month the lining of the uterus builds up for the possiblity of a pregnancy. if the egg is not fertilized the lining is not needed. The lining breaks down, hormones are released causing the muscles to contract and squeeze the lining out.