Losing body hair can usually be attributed to one of five reasons: hormonal disorders, skin conditions, medical illnesses, stress, medications and diet. When you lose all of the hair on your body, it is called Alopecia universalis.
Some hormonal disorders can result in complete body hair loss. Hypothyroidism, a condition where the thyroid is under producing the hormone, may sometimes lead to loosing all of the hair on your body, including the hair on your arms and legs.
Hyperthyroidism is the other extreme, and means that the thyroid is overproducing the hormone. According to hairlossexpert.co.uk, this can result in thinning or total body hair loss, as can pituitary disorders.
Immune system diseases and cancer can result in lapses in the natural hair growth process, leading to loss of hair on your arms, legs and elsewhere.
Dermatitis, psoriasis, eczema, burns and skin injuries often damage the hair follicles and the surrounding cells, causing hair loss on the arms and legs.
Ongoing stress can lead to the production of high levels of cortisol, a stress hormone. This can lead to hair loss on your body, although hair loss on the face and scalp is more typical.
Steroid use can result in hair loss, according to Hair-loss-adviser.com, as can a rare form of Keratosis pilaris, which is a condition where your hair follicles become inflamed and results in plugged follicles.