Digestive system

Decreased production of stomach acid

Shrinking of the stomach

Frequent, often fatal diarrhea

Cardiovascular system (heart and blood vessels)

Reduced heart size, reduced amount of blood pumped, slow heart rate, and low blood pressure

Ultimately, heart failure

Respiratory system

Slow breathing and reduced lung capacity

Ultimately, respiratory failure

Reproductive system

Reduced size of the ovaries and testes

Loss of sex drive (libido)

Cessation of menstrual periods

Nervous system

Apathy and irritability

In children, sometimes intellectual disability

Impaired mental function, particularly in older adults

Numbness or tingling, particularly in the feet and hands

Muscles

Reduced muscle size and strength, impairing the ability to exercise or work

Blood

Anemia

Metabolism (processes the body uses to convert food into energy or to synthesize needed substances)

Low body temperature (hypothermia)

Accumulation of fluid in the arms, legs, and abdomen

Disappearance of fat

Skin and hair

Thin, dry, inelastic skin

Dry, sparse hair that falls out easily

A tendency to bruise easily

Immune system

Impaired ability to fight infections and repair wounds