The result on those who abuse these drugs is often fatal – it puts one’s life, family, the environment, work and activities at great risk. Tolerance builds and the desired effects reduce so much that users have to take more just to get the same effects and to feel 'normal' or avoid a very unpleasant withdrawal state. 

Marijuana (Cannabis)It is a dry, shredded green/brown mix of flowers, stems, seeds, and leaves of the hemp plant Cannabis sativa. It is usually smoked as a cigarette, in blunts or in a pipe. The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol) and it exhibits most of its side effects.  
Effects of marijuana 

(1)  Brain: THC acts in the brain to produce its many effects. The brain is known to be the most affected upon intake of the drug. It affects the part of the brain that is said to be in control of the senses and emotions. It influences pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement. The effects of marijuana include problems with memory and learning, distorted perception, difficulty in thinking and problem solving, loss of coordination, and increased heart rate.
(2) Heart: Within a few minutes after smoking marijuana, the heart begins beating more rapidly and the blood pressure drops. Because of the lower blood pressure and higher heart rate, researchers found that users' risk for a heart attack is four times higher within the first hour after smoking marijuana. 
(3) Lungs: Even infrequent abuse can cause burning and stinging of the mouth and throat, often accompanied by a heavy cough. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers have, such as daily cough and phlegm production, more frequent acute chest illness, risk of lung infections, and a greater tendency to obstructed airways. 
(4) Cancer: Marijuana abuse also has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens. In fact, marijuana smoke contains 50 to 70 per cent more carcinogenic hydrocarbons than does tobacco smoke. 
(5) Effects on learning and social behaviour: Research demonstrates that marijuana has the potential to cause problems in daily life or make a person's existing problems worse. Depression, anxiety, and personality disturbances have been associated with chronic marijuana use. Because marijuana compromises the ability to learn and remember information, the more a person uses marijuana the more he or she is likely to fall behind in accumulating intellectual, job, or social skills. 
(6) Effects during pregnancy: There is evidence that some babies born to women who abused marijuana during their pregnancies display altered responses to visual stimuli, problems with sustained attention and memory, and a high-pitched cry, which may indicate neurological problems in development. 
(7)  Reproductive system: Cannabis has been reported both to enhance and lessen the subjective enjoyment of sex. It also reduces the testosterone levels in men to the lower end of the normal scale, though these levels rise again after the cessation of smoking. The drug also appears to reduce both sperm count and sperm motility. 
(8) Other health effects of marijuana: Some of marijuana's adverse health effects may occur because THC impairs the immune system's ability to fight disease.  It impairs the body's immune system from fighting disease, which can cause a wide variety of health problems. 

HEROIN and abuse effectsHeroin is a natural opiate made from morphine. Heroin is a very strong pain-killer that is abused today. ‘Street’ heroin sold as 'brown' is sometimes used by clubbers as a chill out after a big night out. 
Heroin enters the brain, where it is converted to morphine and binds to receptors that are located in many areas of the brain (and in the body), especially those involved in the perception of pain and in reward. It impairs these receptors located in the brain stem which are important for automatic processes critical for life, such as breathing (respiration), blood pressure, and arousal. After an intravenous injection of heroin, users report feeling a surge of euphoria (“rush”) accompanied by a dry mouth, a warm flushing of the skin, heaviness of the extremities, and clouded mental functioning. Following this initial euphoria, the user goes “on the nod,” an alternately wakeful and drowsy state. 

Adverse effects of heroin on health?Heroin abuse is associated with serious health conditions, including fatal overdose, spontaneous abortion, and particularly in users who inject the drug infectious diseases, including HIV/AIDS and hepatitis. Chronic users may develop collapsed veins, infection of the heart lining and valves, abscesses, and liver or kidney disease. Pulmonary complications, including various types of pneumonia, may result from the poor health of the abuser as well as from heroin’s depressing effects on respiration. In addition to the effects of the drug itself, street heroin often contains toxic contaminants or additives that can clog the blood vessels leading to the lungs, liver, kidneys, or brain, causing permanent damage to vital organs. 

Heroin abuse can cause serious complications during pregnancy, including miscarriage and premature delivery. Children born to addicted mothers are at greater risk of SIDS (sudden infant death syndrome), as well. COCAINE and medical complications of abuseThere are enormous medical complications associated with cocaine use. Some of the most frequent complications are cardiovascular effects, including disturbances in the heart rhythm and heart attacks; such respiratory effects as chest pain and respiratory failure; neurological effects, including strokes, seizure, and headaches; and gastrointestinal complications, including abdominal pain and nausea.

Different routes of cocaine administration can produce different adverse effects. Regularly snorting cocaine, for example, can lead to loss of the sense of smell, nose bleeds, problems with swallowing, hoarseness, and an overall irritation of the nasal septum, which can lead to a chronically inflamed, runny nose. Ingested cocaine can cause severe bowel gangrene, due to reduced blood flow. People who inject cocaine have puncture marks and "tracks," especially in their forearms. Intravenous cocaine users may also experience an allergic reaction, either to the drug, or to some additive in street cocaine, which can result, in severe cases, in death. Because cocaine has a tendency to decrease food intake, many chronic cocaine users lose their appetite and can experience significant weight loss and malnourishment. 

The Liver – Cocaine and crack can damage the liver's ability to detoxify blood, while reducing the production of critical enzymes needed for normal body functions. Hepatitus can be contracted and cause serious liver damage, or lead to cirrhosis and liver cancer. The Intestines – The blood supply is reduced to the intestines, resulting in nausea, diarrhoea, painful cramps, inflammation and even death. 

The reproductive system; Regular use can result in loss of interest in sex, decreased sexual performancce, risk of impotence and infertility; miscarriages, developmental disorders and complications during birth; premature separation of the placenta from the uterus leading to premature births or stillbirths. Psychological and personality changes; Irritability, anxiety, panic attacks, excitable, 'hyper,' erratic, confused, depressed, non-stop babbling, sleeplessness, chronic fatigue, short tempers, bizarre behaviour, agressiveness and violence, suicidal behaviour, paranoia, delusions and hallucinations.

The eyes - Dilation of pupils and blurred vision The throat - Inhaling cocaine vapours causes hoarseness, coughing and constant sore throat . The lungs - Smoking cocaine damages the lung cells' ability to process gases, leaving the user with constant cough and shortness of breath. The heart and blood vessels - Constricts the heart's blood vessels, increasing blood pressure. This may trigger heart attack, heart failure, irregular heart beat and sudden death. Cocaine and crack cause blood vessels to constrict, increasing blood pressure, and risk of heart attack and stroke
The bladder and body weight - Increased need to urinate. Loss of appetite can be so severe that it leads to dramatic weight loss and malnutrition. 

PrecautionsIt is important to know that even though you may feel like dying when coming off of the drug, people most often come out unscathed and a full recovery is completely possible. Below are some ideas to consider when treating drug withdrawal symptoms and finding the help you need.
1.  Give yourself room. Commit yourself fully – let people know that you are quitting and ensure to stick to it. Move away from people that encourage you to start it and build decent friends. It is important to plan out quitting carefully. If you work, try to take some decent time off. 
2. If you plan on quitting, there are things you can do to minimize the pain of withdrawals while quitting:A. Ask a close trusted friend to stay with you during the duration of the withdrawal symptoms. They will have to take care of you as if you had a really bad case of the flu.
B. Keep plenty of fluids handy and foods you can eat available. Fruit drinks, yogurt, oatmeal, bottled water, soups, etc are plain foods that are easy on your stomach and senses while you are ill. It is extremely easy to get dehydrated, so keep this in mind. Also meal replacement shakes may be a great way to deliver nutrient when full meals are not easily consumed. 
C.  See a DOCTOR – very important in the case of an ADDICT. Inform him or her of your quitting, seek help and guidance. The doctor might help you with advice and medicines for the withdrawal effects: nausea, vomiting, diarrhoea or for any other withdrawal symptom that may arise.
E. The most severe of drug abuse symptoms tend to last around five days; however residual affects will slowly continue to fade over a period of time. Remember to give yourself plenty of time to recover. For the sake of your health, try to get as much time off as possible to aid in your recovery.

The first step is 'decision' and staying away from bad friends or colleagues. You make up your mind to stop being a drug abuser. And you quickly move to 'action' - finding ways to help yourself stop. Once stopped, you have to stay stopped - the 'maintenance' stage. This is the trickiest stage for most people. Lapses may occur, and you need to be equipped to cope with them, and overcome them, or find yourself back at the beginning instead of moving on to a better life.

Hard drugs (cocaine, heroin and marijuana) are illegal because of the major health and social risk they pose. Drug abuse has long been associated with crime because its importation and distribution are illegal. Many addicted people turn to theft and prostitution to obtain money to buy the drug. In addition, violent competition between drug dealers has resulted in many murders and the deaths of innocent bystanders. Stay away and don’t attempt to take such drugs – because of the genetic difference a single gram can get you addicted and destroy your life. These are just some of the health and social effects they pose. 

Don't give up on trying to get the help you deserve. Many people do not realize that wrongly using street drugs is a fatal clinical disease, not a moral or character booster. If possible, keep the lines of communication open with your family, co-workers and neighbours as they will most likely be willing to help you... even if you don't think they will now. Use the resources available to you. The more you know and understand, the more the addiction will feel manageable and your confidence in your ability to fight the addiction will increase. Just don't give up!