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Medicinal Use of Cannabis

Medically reviewed by Last updated on Jul 4, 2022.

What is the medicinal use of cannabis?

Cannabis, also called marijuana, pot, weed, or hash, is a drug that comes from the cannabis sativa (hemp plant). The medicinal use of cannabis is also called medical marijuana. The whole plant or its extracts can help control or relieve medical or mental health conditions. The effects may start right away and last for 3 to 4 hours. Cannabis may be taken in the form of a pill, capsule, oil, or mouth spray. Cannabis can also be smoked, baked into food, or made into tea.

What medical conditions or symptoms can cannabis help treat?

  • Pain or inflammation
  • Nausea, vomiting, loss of appetite, or weight loss
  • Tingling or numbness from nerve damage
  • Mood and sleep problems
  • Muscle spasms, tremors (shaking), seizures, or tics
  • Fluid pressure in the eye from glaucoma

What do I need to know about cannabis?

  • Cannabis can vary in quality and strength. It may work well for some people, but not for others. The amount of cannabis needed, when to take it, or if it is working may not be clear. It may interfere with your ability to drive a car or operate machinery.
  • Cannabis taken during pregnancy may prevent an unborn baby from growing normally. Cannabis stays in fat cells and can be transferred slowly to the baby over a long period of time. Cannabis can affect the baby's growth and development.
  • Cannabis can make you feel tired, drunk, dizzy, or high. It can also cause or worsen some of the effects you are trying to relieve. Cannabis can cause anxiety, confusion, decreased memory, or difficulty learning. Cannabis increases the risk for panic disorder, depression, or seeing or hearing things that are not real.
  • Withdrawal can happen if you try to stop cannabis. You feel like you have to start again to relieve or prevent withdrawal symptoms, such as shaky hands. You may feel angry, anxious, nervous, or restless. You may lose your appetite, lose weight, or have problems sleeping.
  • Cannabis may contain harmful substances, such as metals or fungus. Your risk for a lung infection, long-term bronchitis, asthma, or other lung diseases is higher. Your risk for cancer of the head, neck, and lungs is higher if you smoke cannabis. Cannabis may also increase the risk for a heart attack or stroke. When mixed with alcohol, medicine, or drugs, cannabis increases the risk for side effects.
  • Cannabis can cause problems absorbing nutrients if you have liver problems. If you have liver problems, cannabis can cause your liver to scar and not work properly.
  • The risk for cannabis misuse is increased. Misuse means you take cannabis for a different reason than prescribed. For example, your prescription may be for pain relief, but you take it to feel good. You continue even though it causes physical or social problems. This is also called cannabis use disorder.

What are cannabis safety guidelines to follow?

  • See your healthcare provider regularly. Your provider may want to check your blood pressure or make sure cannabis is not affecting other medicines you take.
  • Do not smoke or vape cannabis if you have respiratory problems such as asthma or COPD. Talk to your healthcare provider about cannabis pills, capsules, sprays, or vaporizers, instead of cigarettes.
  • Do not drive or use heavy machinery when you take cannabis.
  • Do not mix alcohol with drugs or medicines.

What do I need to know about cannabidiol (CBD)?

CBD is a chemical produced naturally in cannabis. CBD does not contain tetrahydrocannabinol (THC), the chemical that causes a cannabis high. CBD can help with a substance abuse disorder or to relieve anxiety or depression. CBD may help relieve pain, lower inflammation, and control muscle spasms. CBD may also help control some types of seizures. CBD is an extract. This means it was separated from the rest of the marijuana plant. It is often made into an oil and dropped under the tongue.

Where can I find more information?

  • Substance Abuse and Mental Health Services Administration
    PO Box 2345
    Rockville , MD 20847-2345
    Web Address:
  • National Institute on Drug Abuse
    6001 Executive Boulevard, Room 5213
    Bethesda , MD 20892-9561
    Phone: 1- 301 - 443-1124
    Web Address:

When should I call my doctor?

  • Your symptoms do not improve.
  • You feel you are becoming addicted to or dependent on cannabis.
  • You have questions or concerns about your condition or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.