what is Weight loss and what are it’s main causes

What is Weight loss ?

Unintentional weight loss is a decrease in body weight that is not voluntary. In other words, you did not try to loss the weight by dieting or exercising.
Any condition in which you lose your appetite for an extended period of time—a chronic illness like cancer, for example—can strip you of pounds. One of the most common of these anti-appetite diseases is a chronic infection.

What are the main causes of weight loss?

AIDS

Cancer

Depression

Diarrhea that is chronic (lasts a long time)

Drugs, including amphetamines, chemotherapeutic agents, laxative abuse,
and thyroid medications

Drug abuse

Eating disorders, including anorexia nervosa and bulimia

Hyperthyroidism

Infection

Loss of appetite

Malnutrition

Manipulative behavior (in children)

Painful mouth sores, mouth braces, or a loss of teeth that prevent you from eating normally

Smoking

Poor diet

Increase in exercise or exertion

Dieting

Starvation

Neglect

Anxiety

Aging

Not eating enough

Meal preparation or shopping difficulty – such as in the elderly

Denture difficulties

Loss of appetite – see the various causes of loss of appetite

Athletic training

Mental health disorders

Eating disorder

Anorexia nervosa

Depression

Clinical depression

Grief

Loss of appetite

Anxiety

Certain psychiatric disorders

Substance-related possible causes of weight loss include:

Alcohol abuse

Drug abuse

Amphetamines- cause appetite suppression leading to weight loss.

Some possible digestive condition causing weight loss-

Chronic digestive infection

Inflammatory bowel disease

Stomach ulcer

Weight loss due to gastrointestinal or digestive diseases and disorders

Losing weight due to old age

Beside this there are some another reasons of weight loss:

Hyperthyroidism causing weight loss

When the thyroid gland overproduces certain hormones, unexplained weight loss may occur. Your doctor can order a simple panel of tests to determine if an overactive thyroid is the cause of your weight loss.

Medication and a resulting weight loss

Certain types of medication, including some antidepressants, have been known to cause unexpected weight loss. Read the accompanying packaging on your prescription medications and talk to your pharmacist or doctor if you suspect this might be the cause of your weight loss.

Some more causes of weight loss can be described as:

digestive diseases, such as inflammatory bowel disease or peptic ulcers

hormone imbalances, such as an increased thyroid hormone level known as hyperthyroidism

increased level of physical activity, due to exercise or manual labor

infections, such as HIV or tuberculosis

intake of fewer calories

medicine or drugs, such as amphetamines, ephedrine, cocaine, heroin, or alcohol

psychiatric conditions, such as depression, anorexia, or schizophrenia

severe kidney, liver, or heart disease.

conditions that affect the ability of the intestines to absorb food and other nutrients

diabetes, a condition that results in high blood glucose levels