Smoking and your health

One of the substances in tobacco is an addictive drug called nicotine. Nicotine reaches your brain in seconds. It makes you feel more energized for a little while. As that effect subsides, you feel tired and crave more.

Smoking increases the risk of macular degeneration, cataracts and poor eyesight. It can also weaken your sense of taste and sense of smell, so food may become less enjoyable.

Your body has a stress hormone called cortisol, which lowers the effects of nicotine. If you're under a lot of stress, you will need more nicotine to get the same effect.

Physical withdrawal from smoking can impair your cognitive functioning and make you feel anxious, irritated, and depressed. Withdrawal can also cause headaches and sleep problems.

When you inhale smoke, you take in substances that can damage your lungs. Over time, your lungs lose their ability to filter harmful chemicals. Coughing can't clear out the toxins sufficiently, so these toxins get trapped in the lungs. Smokers have a higher risk of respiratory infections such as colds, flu and pneumonia.

In a condition called emphysema, the air sacs in your lungs are damaged. In chronic bronchitis, the lining of the tubes of the lungs becomes inflamed. Over time, smokers are at increased risk of developing these forms of chronic obstructive pulmonary disease (COPD). Long-term smokers are also at increased risk of lung cancer.

Withdrawal from tobacco products can cause temporary congestion and respiratory pain as your lungs begin to clear out.

Children whose parents smoke are more prone to coughing, wheezing, and asthma attacks than children whose parents don't. They also tend to have more ear infections. Children of smokers have higher rates of pneumonia and bronchitis.

Smoking damages your entire cardiovascular system. When nicotine hits your body, it gives your blood sugar a boost. After a short time, you're left feeling tired and craving more. Nicotine causes blood vessels to tighten, which restricts the flow of blood (peripheral artery disease). Smoking lowers good cholesterol levels and raises blood pressure, which can result in stretching of the arteries and blockages. Smoking raises the risk of forming blood clots.

Blood clots and weakened blood vessels in the brain increase a smoker's risk of stroke. Smokers who have heart bypass surgery are at increased risk of recurrent heart disease. In the long term, smokers are at greater risk of blood cancer (leukemia).

There's a risk to non-smokers, too. Breathing secondhand smoke has an immediate effect on the cardiovascular system. Exposure increases your risk of stroke, heart attack, and coronary heart disease.

Some of the more obvious signs of smoking involve the skin. The substances in tobacco smoke actually change the structure of your skin. Smoking causes discoloration, wrinkles, and premature ageing. Your fingernails and the skin on your fingers may have yellow staining from holding cigarettes. Smokers usually develop yellow or brown stains on their teeth. Hair holds on to the smell of tobacco long after you put your cigarette out. It even clings to non-smokers.

Smokers are at great risk of developing oral problems. Tobacco use can cause gum inflammation (gingivitis) or infection (periodontitis). These problems can lead to tooth decay, tooth loss and bad breath.

Smoking increases risk of cancer of the mouth, throat, larynx, and esophagus. Smokers have higher rates of kidney cancer and pancreatic cancer. Even cigar smokers who don't inhale are at increased risk of mouth cancer.

Tobacco smoke has an effect on insulin, making it more likely that you'll develop insulin resistance. That puts you at increased risk of type 2 diabetes. When it comes to diabetes, smokers tend to develop complications at a faster rate than non-smokers.

Smoking also depresses appetite so you may not be getting all the nutrients your body needs.

Restricted blood flow can affect a man's ability to get an erection. Both men and women who smoke may have difficulty achieving orgasm and are at higher risk of infertility. Women who smoke may experience menopause at an earlier age than non-smoking women. Smoking increases a woman's risk of cervical cancer.

Smokers experience more complications during pregnancy including miscarriage, problems with the placenta and premature delivery.

Pregnant mothers who smoke, or are exposed to secondhand smoke are more likely to have a baby with low birth weight, birth defects and a higher risk of sudden infant death syndrome (SIDS). Newborns who breathe in smoke suffer more ear infections and asthma attacks.