Smoking cigarettes has many health risks for everyone. However, the younger you are when you start smoking, the more problems it can cause. People who start smoking before the age of 21 have the hardest time quitting. Teens who smoke are also more likely to use alcohol and illegal drugs.

The problem is not just cigarettes. Spit tobacco, e-cigarettes, and cigars are not safe alternatives to cigarettes. Low-tar and additive-free tobacco products are not safe either.

Young people who do not start using tobacco by age 18 will most likely never start.

Centers for Disease Control and Prevention

Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back and forth between your body and your brain. It is protected by your vertebrae, which are the bone disks that make up your spine. If you have an accident that damages the vertebrae or other parts of the spine, this can also injure the spinal cord. Other spinal cord problems include:

• Tumors
• Infections such as meningitis and polio
• Inflammatory diseases
• Autoimmune diseases
• Degenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy

Symptoms vary but might include pain, numbness, loss of sensation and muscle weakness. These symptoms can occur around the spinal cord, and also in other areas such as your arms and legs. Treatments often include medicines and surgery.

Cholesterol is a waxy, fat-like substance that's found in all the cells in your body. Your body needs some cholesterol to work properly. But if you have too much of it in your blood, it can stick to the walls of your arteries and narrow or even block them. This puts you at risk for coronary artery disease and other heart diseases.

Cholesterol is made by your liver. It travels through the blood on proteins called lipoproteins. One type of lipoprotein, LDL, is sometimes called the "bad" cholesterol. A high LDL level leads to a buildup of cholesterol in your arteries. Another type, HDL, is sometimes called the "good" cholesterol. It carries cholesterol from other parts of your body back to your liver. Then your liver removes the cholesterol from your body.

Statins are a type of cholesterol medicine. Your health care provider may prescribe them if you have high cholesterol and making lifestyle changes does not lower your cholesterol enough. Statins are the most common medicines used to treat high cholesterol.

Statins lower LDL cholesterol by slowing down how much cholesterol the liver makes. They also increase your liver's ability to remove LDL cholesterol that is already in the blood. This can slow the formation of plaques in your arteries. Studies have shown that statins lower the risk of heart attack and stroke in people with high LDL cholesterol.

Statins can lower your triglyceride level as well. Triglycerides are another type of fat in your blood that can raise the risk of heart disease. Statins may also increase your HDL cholesterol.

Statins usually don't cause side effects, but they may raise the risk of type 2 diabetes. However, this mainly happens in people already at high risk of diabetes, such as those who are overweight or have obesity, prediabetes, or metabolic syndrome.

Statins may also cause abnormal results on liver enzymes tests, but actual liver damage is very rare. Another uncommon side effect is muscle damage. In rare cases, this muscle damage can lead to muscle pain and kidney damage.

You should not take statins if you are pregnant or breastfeeding. They are also not recommended for people who have certain types of liver disease.

To safely take statins, you should:

• Take your statin as prescribed. You should not stop taking this medicine on your own, since that can lead to a serious problem or, in rare cases, even cause death. Talk to your provider if you have any concerns about your statin or if you would like to stop or change to a different treatment.
• Ask your provider which other medicines, supplements, or foods you should avoid. Some of these can interact with statins and cause serious side effects or make statins less effective. For example, grapefruit (fresh or as juice) affects how your liver breaks down some statins.
• Tell your provider about any symptoms or side effects you are having. Sometimes, people report muscle problems while taking statins. If you start having muscle pain, your provider may order a blood test to look look for muscle damage. The pain may go away if you switch to a different statin. Muscle damage with statins is rare, and your muscles may heal when you switch to a different medicine.

Your stomach is an organ between your esophagus and small intestine. It is where digestion of protein begins. The stomach has three tasks. It stores swallowed food. It mixes the food with stomach acids. Then it sends the mixture on to the small intestine.

Most people have a problem with their stomach at one time or another. Indigestion and heartburn are common problems. You can relieve some stomach problems with over-the-counter medicines and lifestyle changes, such as avoiding fatty foods or eating more slowly. Other problems like peptic ulcers or GERD require medical attention.

You should see a doctor if you have any of the following:

• Blood when you have a bowel movement
• Severe abdominal pain
• Heartburn not relieved by antacids
• Unintended weight loss
• Ongoing vomiting or diarrhea

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Your tongue helps you taste, swallow, and chew. You also use it to speak. Your tongue is made up of many muscles. The upper surface contains your taste buds.

Problems with the tongue include:

• Pain
• Swelling
• Changes in color or texture
• Abnormal movement or difficulty moving the tongue
• Taste problems

These problems can have many different causes. Treatment depends on the underlying problem.