Addiction wired. Smoking as a teen can lead to a more intense nicotine addiction. A teen's brain is more susceptible to nicotine than an adult brain. When your teen brain is exposed to nicotine, it develops twice as many specialized nicotine receptors as an adult's brain. This means that you are more likely to become a lifelong smoker, compared to somebody who first tries smoking as an adult

Brain damage. Smoking can damage your developing brain by stunting the growth of the prefrontal cortex, the part of the brain responsible for "executive" functions (like impulse control and weighing the consequences of your actions). This can alter your ability to make rational decisions about your health, like the decision to quit smoking.

Nerve damage. The hearing nerve pathways aren’t fully developed in teens. Exposure to the toxic chemicals in smoke may cause permanent damage to these nerve pathways and set you up for hearing loss later in life.

Decreased night vision. Nicotine restricts the production of rhodopsin, a chemical pigment necessary for night vision. This can make driving at night dangerous.

Dirty mouth. Smoking dulls the taste buds on your tongue. You may have to put extra salt or hot sauce on your food to make it taste good. Smoking also irritates the lining of the mouth, which can lead to mouth sores and ulcers. Smoking stains your teeth yellow, and gives you nasty bad breath that can’t be covered up with gum.

Zits. The combination of stress and smoking can cause you to breakout and have more zits that last longer.

Stressed heart. Smoking raises your blood pressure and puts stress on your heart. Teens who smoke show signs of heart stress, including physical changes to the heart muscle itself, and a higher resting heart rate. These are warning signs that the heart is working too hard.

Sticky blood. Smoking makes your blood thick and sticky. The stickier your blood, the harder your heart must work to move it around your body. This puts stress on your heart. Sticky blood is also more likely to form deadly blood clots that block blood flow to your heart, brain, and legs. If you are on the birth control pill, or other hormonal methods of birth control (like the pill, patch, or vaginal ring), your risk for blood clots is even higher.

Fatty deposits. Smoking increases the amount of cholesterol and unhealthy fats circulating in the blood. This can lead to fatty deposits on the walls of the arteries, the vessels that carry blood from the heart to the rest of the body. Fatty streaks can often be seen on the artery walls of teens who smoke. This is an early sign of heart disease.

Short of breath. Smoking causes inflammation in the small airways and tissues of your lungs. Inflammation can make your chest feel tight, cause you to wheeze, or feel short of breath.

Dead alveoli. Smoking destroys the tiny air sacs, or alveoli, in the lungs that allow oxygen exchange. When you smoke, you are damaging some of those air sacs. Alveoli don’t grow back, so when you destroy them you have permanently destroyed part of your lungs.

Smaller lungs. Teen lungs are still growing; smoking when you’re a teen can stunt the growth of your lungs. Teens who smoke have smaller, weaker lungs than teens that don’t smoke.

Dead cilia. Your airways are lined with tiny brush like hairs, called cilia. As air is inhaled, the cilia move back and forth, sweeping out mucus and dirt so your lungs stay clear. Smoking temporarily paralyzes and even kills cilia.

Damaged DNA. Your body is made up of cells, containing genetic material, or DNA, that act as an “instruction manual” for cell growth and function. Every single puff of a cigarette causes damage to DNA. When DNA is damaged, the “instruction manual” gets messed up and the cell can begin growing out of control and create a cancer tumor.

More belly fat. Teens who smoke have more belly fat than non-smokers. Belly fat increases your chances of getting Type 2 Diabetes. It also makes it harder to control diabetes if you already have it.

Lower estrogen levels. Smoking lowers a female’s level of estrogen. Low estrogen levels can cause dry skin, thinning hair, and memory problems.

Failure to launch. Smoking increases the risk of erectile dysfunction or impotence—the inability to achieve or maintain an erection. Tar and chemicals in cigarette smoke cause damage to the blood vessels and arteries that deliver blood to the penis. Without adequate blood flow, the penis can’t get or stay hard. Smoking also raises your blood pressure, which can restrict blood flow to the penis.

High white blood cell count. When you smoke, the number of white blood cells (a.k.a. the cells that defend your body against infectious disease and foreign materials) stays high. This is a sign that your body is under stress –constantly fighting against the inflammation and damage caused by tobacco. A high white blood cell count is like an SOS from your body, letting you know that you have been injured.

Longer to heal. Nutrients, minerals, and oxygen are all supplied to the tissue via the bloodstream. Nicotine causes blood vessels to constrict, which decreases the levels of nutrients supplied to wounds. As a result, wounds take longer to heal.

Weaker immune system. Cigarette smoke contains high levels of tar and other chemicals, which can make your immune system less effective at fighting off infections. This means you are more likely to get sick and miss out on things that you want to do.

Tired muscles. When you smoke, less blood and oxygen flow to your muscles. This makes it harder to build muscle. The lack of oxygen also makes muscles tire more easily.

Disrupted bone growth. Your skeleton grows rapidly during your teen years. Bones must constantly form new bone tissue to stay strong and healthy. Ingredients in cigarette smoke disrupt the natural cycle of bone health. Your body is less able to form healthy new bone tissue, and it breaks down existing bone tissue more rapidly.

Become addicted. Exposing the brain to nicotine during the teen years can cause permanent changes in the way the brain works and responds to rewards and consequences. As an adult, you may be more susceptible to other addictions (like to alcohol and drugs).

Memory problems. Adults with damage to the prefrontal cortex caused by smoking often have problems with attention and memory. They may also have trouble with certain tasks that are necessary to succeed at their job, such as planning, reasoning, and problem-solving.

Hearing loss. Smoking also reduces the oxygen supply to the cochlea, a snail-shaped organ in the inner ear. This results in permanent damage to the cochlea and mild to moderate hearing loss.

Blindness. Over time, smoking causes physical changes in the eyes that can threaten your eyesight. Smoking increases your risk of developing cataracts and macular degeneration (both can lead to blindness).

Cavities. Smoking takes a toll on your mouth. Smokers have more oral health problems than non-smokers. You are more likely to have cavities and lose your teeth at a younger age. You are also more likely to get cancers of the mouth and throat.

Smoker’s face. Over time, smoking can cause your skin to be dry and lose elasticity, leading to wrinkles and stretch marks. Your skin tone may become dull and grayish. By your early 30′s, wrinkles will probably begin to appear around your mouth and eyes, adding years to your face.

Weak heart. Over time, stress on the heart can weaken it, making it less able to pump oxygenated blood to other parts of your body. Carbon monoxide from the inhaled cigarette smoke also contributes to a lack of oxygen, making the heart work even harder. This increases the risk of heart disease, including heart attacks.

Heart attack/stroke. Over time, thick, sticky blood damages the delicate lining of your blood vessels. This damage can increase your risk for a heart attack or stroke.

Foot amputation. Over time, cholesterol, fats and other debris build up on the walls of your arteries. This build-up narrows the arteries and blocks normal blood flow to the heart, brain, and legs. Blocked blood flow to the heart or brain can cause a heart attack or stroke. Blockage in the blood vessels of your legs could result in the amputation of your toes or feet.

Scarred lung. Continued inflammation builds up scar tissue, which leads to permanent scarring of your lung tissue and airways. The scar tissue causes physical changes to your lungs and airways that can make breathing hard. Years of lung irritation can give you a chronic cough with mucus.

Emphysema. When enough alveoli are destroyed, the disease emphysema develops. Emphysema causes severe shortness of breath, because lungs can no longer exchange oxygen. Emphysema gets worse over time if you continue to smoke. You could end up on oxygen or die.

Stunted lungs. If you smoke as a teen, your lungs will never be able to grow to their full capacity. Smaller lung capacity makes it harder to exercise. You will get tired more easily. And as an adult, you may experience earlier aging of your lungs.

Respiratory infections. When you smoke your body makes more mucus and the cilia can no longer clear your lungs. This makes you more at risk for infection. Smokers get more colds and respiratory infections than non-smokers.

Cancer. The damage smoking does to your DNA adds up. Your body tries to repair the damage that smoking does to your DNA, but over time smoking can wear down this repair system and lead to cancer (like lung cancer, pancreatic cancer, stomach cancer, and cancers of the mouth, throat, esophagus and sinuses). In fact, one third of all cancer deaths are caused by tobacco.

Bigger belly. Adults who smoke have bigger bellies and less muscle than non-smokers. And they’re more likely to develop Type 2 Diabetes, even if they don’t smoke every day. Diabetes is a serious disease that can lead to blindness, heart disease, kidney failure, nerve damage, and amputations.

Harder to get pregnant. Adult women who smoke have a harder time getting pregnant and having a healthy baby. Smoking can also lead to early menopause, which increases your risk of developing certain diseases (like heart disease, ovarian cancer and osteoporosis).

Difficulty having kids. Toxins from cigarette smoke can damage the genetic material in sperm. Males who smoke have more damaged sperm than males who don’t. Damaged sperm can cause infertility or genetic defectsproblems in their children. Smoking is also associated with having a low sperm count and having sperm that are “poor swimmers” which can further reduce the odds of having a child.

Damage to heart/lungs. If you continue to smoke as an adult, your white blood cell count will stay abnormally high from the repeated smoking “injuries” to your heart, blood vessels, lungs, and other important organs. White blood cells counts that stay elevated for a long time are linked with an increased risk of heart attacks, strokes, and cancer.

Painful skin ulcers. Slow wound healing increases the risk of infection, after an injury or surgery. Painful skin ulcers can develop if adequate blood flow fails to reach skin tissues, causing the tissue to slowly die.

Arthritis. Continued weakening of the immune system can make you more vulnerable to autoimmune diseases like rheumatoid arthritis. You may experience serious complications from viruses like the flu. It also decreases your body’s ability to fight off cancer!

Muscle deterioration. Smokers have more muscle aches and pains than non-smokers. Also, smoking accelerates the breakdown of muscle tissue. Over time, muscle deterioration can lead to weakness and loss of muscle function.

More broken bones. Over time, smoking leads to a thinning of bone tissue and loss of bone density. This causes bones to become weak and brittle. Compared to non-smokers, smokers have a higher risk of bone fractures, and their broken bones take longer to heal.

Broken addiction cycle. Quitting smoking can re-wire your brain and help break the cycle of addiction. The large number of nicotine receptors in your brain will return to normal levels after about a month of being quit.

Fully developed brain. During the teenage years your brain is in a critical development period. Brain development isn’t complete until around the age 25. Quitting smoking now will allow your prefrontal cortex to develop normally, and set you up for success as an adult.

Sharp hearing. Quitting smoking will keep your hearing sharp. Remember, even mild hearing loss can cause problems (like not clearly hearing homework instructions and doing them wrong).

Better vision. Quitting smoking will improve your night vision and help preserve your overall vision by stopping the damage that smoking does to your eyes.

Clean mouth. Nobody likes a dirty mouth. After a few days without cigarettes, your smile will be brighter and your tastebuds will kick back in. Quitting smoking now will keep your mouth healthy and kissable for years to come.

Clear skin. Quitting smoking is better than any zit cream or anti-aging lotion! It can help clear up your skin, and protect it from premature aging and wrinkling.

Decreased heart risks. Smoking is the leading cause of heart attacks and heart disease. But many of these heart risks can be reversed simply by quitting smoking. Quitting can lower your blood pressure and heart rate almost immediately. Your risk of a heart attack declines within 24 hours.

Thin blood. When you quit smoking, your blood will become thinner and less likely to form dangerous blood clots. Your heart will also have less work to do, since it will be able to move the blood around your body more easily.

Lower cholesterol. Quitting smoking will not get rid of the fatty deposits that are already there. But it will lower the levels of cholesterol and fats circulating in your blood, which will help to slow the build up of new fatty deposits in your arteries.

Stop lung damage. Scarring of the lungs is not reversible. That is why it is important to quit when you are young, before you do permanent damage to your lungs.

Prevent emphysema. There is no cure for emphysema. But quitting when you are young, before you have done years of damage to the delicate air sacs in your lungs, will help protect you from developing emphysema later.

Fully developed lungs. Quitting smoking at any age is beneficial, but quitting now will allow your growing lungs to reach their full capacity. This will help you be a healthier and more physically fit adult.

Return of cilia. Cilia start to re-grow and regain normal function very quickly after you quit smoking. They are one of the first things in your body to heal. People sometimes notice that they cough more than usual when they first quitting smoking. This is a sign that the cilia are coming back to life.

Lower cancer risk. Quitting smoking will prevent new DNA damage from happening, and can even help repair the damage that has already been done. Although quitting smoking at any age is beneficial, quitting when you are young is one of the best ways to lower your risk of getting cancer in the future.

Smaller belly. Quitting smoking will reduce your belly fat and lower your risk of diabetes. If you already have diabetes, quitting can help you keep your blood sugar levels in check.

Normal estrogen levels. Quitting smoking will help you be a healthy woman now and later. Your estrogen levels will gradually return to normal after you quit smoking. And if you hope to have children someday, quitting smoking right now will increase your chances of a healthy pregnancy in the future.

Sexual healing. If you quit smoking now, you can lower your chances of erectile dysfunction and improve your chances of having a healthy sexual life as an adult.

Normal white blood cell count. When you quit smoking, your body will begin to heal from the injuries that smoking caused. Eventually, your white blood cell counts will return to normal and will no longer be on the defensive.

Proper healing. Quitting smoking will improve blood flow to wounds, allowing important nutrients, minerals, and oxygen to reach the wound and help it heal properly.

Stronger immune system. When you quit smoking, your immune system is no longer exposed to tar and other chemicals. It will become stronger, and you will be less likely to get sick.

Strong muscles. Quitting smoking will help increase the availability of oxygen in your blood, and your muscles will become stronger and healthier.

Stronger bones. Taking care of your bones during your teen years builds the foundation for healthy bones for the rest of your life. Quitting smoking can reduce your risk of fractures, both now and later in life. Keep your bones strong and healthy by quitting now.