The cause of death due to starvation is usually an infection or the result of tissue breakdown. This is due to the body becoming unable to produce enough energy to fight off bacteria and viruses. The final stage of starvation includes signals like hair color loss, skin flaking, swelling in the extremities, and a bloated belly. Even though they may feel hunger, people in the final stage of starvation usually cannot eat enough food to recover. Causes
The body expends more energy than it takes in. This imbalance can arise from one or more medical conditions or circumstantial situations, which can include:
Medical reasons

Anorexia nervosa
Bulimia nervosa
Eating disorder, not otherwise specified
Celiac disease
Coma
Major depressive disorder
Diabetes mellitus
Digestive disease
Constant vomitingCircumstantial causes

Child, elder, or dependant abuse
Famine for any reason, such as political strife and war
Hunger striking
Excessive fasting
Poverty
Torture

Biochemistry
With a typical high-carbohydrate diet, the human body relies on free blood glucose as its primary energy source. Glucose can be obtained directly from dietary sugars and by the breakdown of other carbohydrates. In the absence of dietary sugars and carbohydrates, glucose is obtained from the breakdown of stored glycogen. Glycogen is a readily-accessible storage form of glucose, stored in notable quantities in the liver and skeletal muscle. After the exhaustion of the glycogen reserve, and for the next two to three days, fatty acids become the principal metabolic fuel. At first, the brain continues to use glucose. If a non-brain tissue is using fatty acids as its metabolic fuel, the use of glucose in the same tissue is switched off.
The phonatory muscles are divided into adductors (lateral cricoarytenoid muscles, arytenoid muscles) and tensors (cricothyroid muscles, thyroarytenoid muscles). Intrinsic
The intrinsic laryngeal muscles are responsible for controlling sound production. Cricothyroid muscle lengthen and tense the vocal cords. Posterior cricoarytenoid muscles abduct and externally rotate the arytenoid cartilages, resulting in abducted vocal cords. Lateral cricoarytenoid muscles adduct and internally rotate the arytenoid cartilages, increase medial compression. Transverse arytenoid muscle adduct the arytenoid cartilages, resulting in adducted vocal cords. Oblique arytenoid muscles narrow the laryngeal inlet by constricting the distance between the arytenoid cartilages. Thyroarytenoid muscles narrow the laryngeal inlet, shortening the vocal cords, and lowering voice pitch. The internal thyroarytenoid is the portion of the thyroarytenoid that vibrates to produce sound.Notably the only muscle capable of separating the vocal cords for normal breathing is the posterior cricoarytenoid. If this muscle is incapacitated on both sides, the inability to pull the vocal cords apart (abduct) will cause difficulty breathing. Bilateral injury to the recurrent laryngeal nerve would cause this condition. It is also worth noting that all muscles are innervated by the recurrent laryngeal branch of the vagus except the cricothyroid muscle, which is innervated by the external laryngeal branch of the superior laryngeal nerve (a branch of the vagus). Additionally, intrinsic laryngeal muscles present a constitutive Ca2+-buffering profile that predicts their better ability to handle calcium changes in comparison to other muscles. This profile is in agreement with their function as very fast muscles with a well-developed capacity for prolonged work.