Full-body cramps are painful involuntary muscle contractions, which are known to accompany heat exhaustion, according to the Dallas Morning News. Side effects of some drugs, poor blood circulation, dehydration, and certain medical conditions are among the many possible causes of body cramps, explains WebMD. Pinched or compressed nerves along the spine, known as lumbar stenosis, may induce cramping pain in the arms and legs, which walking tends to aggravate, says Mayo Clinic.
Sitting or standing for too long in a static position sometimes causes muscle cramps. Mineral deficiencies, including potassium, calcium or magnesium may cause cramps. Some medications that treat hypertension, such as diuretics, may deplete some minerals, notes Mayo Clinic.
A sudden onset of hyponatremia, or low blood sodium, develops when there is an upset in the body's water and sodium balance. It is a medical emergency that produces painful cramps but it can also produce seizures, advises Healthline.
Cindy Trowbridge, an associate professor of kinesiology at the University of Texas, likens cramping to rigor mortis. Trowbridge explains that the pain induces muscle contractions powerful enough to interfere with, or prevent, voluntary movement. The victim's bodily responses get caught up in a painful cycle of more pain producing more contractions, states the Dallas Morning News.