d. Dehydration: Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).

e. Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck.

f. Massage: The manipulation of muscle and connective tissue to enhance the function of those tissues and promote relaxation and well-being. Therapeutic massage can ease tension and reduce pain.

g. Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain results from nerve stimulation. Pain may be contained to a discrete area, or it can be more diffuse.

h. Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.

i. Temporomandibular joint (TMJ) : The joint that connects the lower jaw to the facial bones.