Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link
Quick Facts



The Manual's Editorial Staff

Last full review/revision Jul 2021| Content last modified Jul 2021
Click here for the Professional Version
Get the full details

Why is smoking tobacco bad for my health?

People smoke tobacco in cigarettes, cigars, and pipes. Tobacco smoke has many harmful chemicals that cause problems in your whole body, not just your lungs.

Breathing in smoke from someone else who is smoking, called second-hand smoke, can cause the same health problems as smoking yourself.

Smoking while pregnant can hurt the unborn baby and cause:

What about e-cigarettes?

Electronic cigarettes, called e-cigarettes, and vapes contain liquid nicotine and flavored chemicals, not tobacco. The e-cigarette or vape heats the liquid into a vapor that you breathe in.

  • You can become addicted to e-cigarettes or vapes if they contain nicotine because nicotine is addictive

  • Because nothing burns in an e-cigarette or vape, you don't get the same problems caused by smoke

  • Certain substances in the vapor, such as THC or vitamin E acetate, appear to lead to severe lung injury and sometimes death

  • E-cigarettes and vapes haven't been around long enough for doctors to know the long-term risks

What if a child swallows ?

A child who has eaten a cigarette or anything with nicotine (such as nicotine gum) needs emergency treatment. Doctors will treat the child for nicotine poisoning.

What are the effects of smoking?

Immediate effects

You often don't feel anything from smoking, but you may feel:

  • More energy

  • Better able to concentrate

  • Less hungry

If you try smoking and aren't used to it yet, you may feel sick to your stomach, flushed, or both.

Long-term effects

Smoking hurts nearly every organ in your body. The main smoking-related problems are:

Smoking also makes it more likely you will have:

Smoking also causes:

  • Dry and wrinkled skin

  • Thinning hair

  • Yellow teeth

  • Weight loss

Withdrawal symptoms

If you quit smoking, you may go through withdrawal. Withdrawal is when you feel sick after you stop taking a drug that you took for a long time. Smoking withdrawal can cause you to:

  • Want to smoke

  • Feel moody, anxious, sleepy, or sad

  • Have headaches and trouble concentrating

  • Tremble (tremor)

  • Have an upset stomach and gain weight

Should I talk to my doctor about my smoking?

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read
Test your knowledge
Care Providers - Family and Friends
Some older people require caregivers to provide help and care with activities of daily living. Of the several different types of people who can serve as a caregiver, which of the following is the most common?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID