What could be the cause of constant muscle spasms in the body for a male, specifically the chest area near the heart. has spread to teste's and head.

Fibromyalgia ?: 18y male has ongoing "muscle spasms" & mentions head, groin & chest. If lab tests are normal consider Fibromyalgia & because so many different body regions & tissues are involved. See a Rheumatologist for an opinion. In males, Fibromyalgia seems to follow upon trauma & mechanical injuries to low back & pelvis; especial after extreme sport injures such as skateboarding/snowboarding.

Fibromyalgia: diagnosis is made by evaluating pain or aching in multiple large groups of muscles not testicles or head: get examined, evaluated, diagnosed and treated. http://www.mayoclinic.org/diseases-conditions/fibromyalgia/basics/symptoms/con-20019243