Pounding sensation in certain body parts, subsides on pressing the area hard. Cause?

For as long as I can remember I ve had this pounding sensation in certain parts of my body hit me it random times. Usually it s irregular, maybe once a month or less, but lately it has been happening almost every day. It feels as if someone is taking a hammer from the inside and hitting upwards. The only way to stop the pain is to press down on the area very hard. It is extremely painful. Usually I double over in pain when it happens. It has occurred all over my body but usually near my lower ribs, on both sides, also in my arms, my stomach , and a few times, my legs.