Starvation initially causes headaches, weakness, tiredness, cramps and dizziness. Denied glucose, the body enters a hypoglycemic state and confusion, irritability and increased heart-rate follow. As starvation continues, the person may experience nightmares, lack of coordination and fainting. The final stages of starvation include coma and death.
An otherwise healthy person dies after 8 to 12 weeks of total starvation, but can survive longer if glucose intake is high enough to avoid severe hypoglycemia. During semi-starvation, the body cannibalizes itself. Dehydration occurs as fat stores deplete and stored fluids exit the body through diarrhea. The kidneys are unable to process the waste from fat-breakdown quickly enough and fluid pools under the skin, causing swelling. As fat-soluble vitamins disappear, vision decreases, bones become more brittle and blood clots less efficiently. After fat stores are exhausted, the body consumes muscle for energy, causing weakness, fatigue, loss of coordination and severe pain. The immune system weakens as energy diverts to organ and brain functions and the body becomes less able to stave off infection. The stomach stops producing digestive acid, and digestion of even limited amounts of food becomes ineffective. Lack of nutrients and self-cannibalism causes internal organs to shrink and ultimately fail. Finally, the brain degenerates, resulting in hallucinations, convulsions and death.