Of all the drugs that alter a person\u2019s looks, methamphetamine (meth) causes the most overt visible signs of abuse. Meth abuse wreaks havoc on the entire body, destroying tissues and blood vessels and inhibiting the body's ability to repair itself. The effects of meth include a decrease in appetite, resulting in muscle degradation, unhealthy loss of body mass, atrophy and a skeletal appearance. Meth abuse also causes the facial structure to undergo a horrific transformation due to serious skin issues and tooth loss. Skin: Low blood flow, destroyed blood cells and poor hygiene associated with meth abuse result in dull skin devoid of a natural glow, loss of elasticity and an inability to heal. Meth effects cause drastic visible changes to a user\u2019s skin, such as severe acne, premature aging and sagginess. Pale skin color is associated with physical stress and frequent illnesses caused by a weakened immune system. Smoking meth causes prematurely wrinkled skin with a leather-like appearance. Meth bugs \u2013 Some people who abuse meth believe they are infested with bugs creeping on top of or underneath their skin. In studies of meth users admitted to drug treatment facilities, about 40% reported meth bugs. This figure rose to 70% in individuals with a history of psychosis. At first glance, a doctor may think these sores are scabies. Multiple pockmarks on a person\u2019s face and extremities, or recurrent skin abscesses in these areas are often a sign of chronic meth abuse. Meth addicts may pick or scratch their skin incessantly to get rid of the imaginary bugs, sometimes tearing the flesh open. Safety pins, needles or other sharp objects may be used to remove meth bugs. Also called delusions of parasitosis or formication, some people think the drug itself is coming out of their skin rather than insects. Open sores typically affect the face and arms, making the sufferer vulnerable to abscesses, as well as staph, strep and other infections. A study on meth users found staph infections in 61% of abscesses and 53% of purulent wounds treated at U.S. hospital emergency rooms. These statistics are likely low because many meth addicts self-treat their wounds. Rashes and abscesses \u2013 In addition to acne and sores associated with meth bugs, the byproducts produced in the meth manufacturing process can be irritating to the skin and cause lesions that look like a rash. Battery acid used to make meth and dirty needles used to inject it can cause skin abscesses and other types of infections. Many of these skin manifestations clear up when meth use ends, but some can persist for months or even years. Eyes: Few studies have been published on the ocular side effects of meth. Heavy users of meth can develop several types of eye conditions, leading to permanent eye damage and vision impairment. Visible side effects include involuntary eye twitching, related to a disruption in functions of the central nervous system. In some cases, pupils can remain dilated for up to 48 hours after meth use. Teeth: The condition known as "meth mouth" is the visible side effect many people associate with meth abuse. Meth can cause blackened, stained, rotting or crumbling teeth and gum disease. A study of 571 meth users found 96% had cavities, 58% suffered from untreated tooth decay and 31% had six or more missing teeth. Even in young or short-term users, teeth are often beyond repair and need to be pulled. A 2000 study in the Journal of Periodontology found that users who snorted the drug had significantly worse tooth decay than users who smoked or injected it, although all users experienced dental problems. Some reports attribute tooth decay to the corrosive effects of the chemicals found in the drug, such as anhydrous ammonia (found in fertilizers), red phosphorus (used in matchboxes) and lithium (an element in batteries). When smoked or snorted, these chemicals likely erode the tooth's protective enamel coating. Strong evidence indicates the degree of tooth decay is linked to a combination of side effects associated with the meth high. These include shrinking blood vessels, compulsive grinding of the teeth and dry mouth, exacerbated by craving high-calorie, carbonated and sugary beverages. The meth high can last as long as 12 hours, which equates to long periods of poor oral hygiene. Meth wreaks havoc on the brain and body, resulting in insidious side effects, some of which aren\u2019t reversible. It\u2019s crucial that people addicted to meth get meth addiction treatment as early as possible to help reverse some of the psychological and physical effects and prevent permanent damage.