Chemotherapy involves using medicines that have strong chemicals to kill fast-growing cells in the body.

People most often receive chemotherapy medicines to treat cancer, since cancer cells grow and multiply much more quickly than most cells in the body. The treatment also can keep the cancer from growing or may shrink the cancer to help people with advanced cancers live longer.

Many different chemotherapy medicines are available. Healthcare professionals may use chemotherapy medicines alone or in combination to treat a wide variety of cancers.

Though chemotherapy can help treat many types of cancer, these medicines can have side effects. Some chemotherapy side effects are mild and treatable. Others can cause serious complications.

Chemotherapy is used to kill cancer cells in people with cancer.

There are a variety of settings in which chemotherapy may be used in people with cancer:

• To cure the cancer without other treatments. Chemotherapy can be used as the primary or only treatment for cancer.
• After other treatments, to kill hidden cancer cells. Chemotherapy can be used after other treatments, such as surgery, to kill any cancer cells that might remain in the body. Healthcare professionals call this adjuvant therapy.
• To prepare the body for other treatments. Chemotherapy can be used to make a cancer smaller so that other treatments, such as radiation and surgery, are possible. Healthcare professionals call this neoadjuvant therapy.
• To ease signs and symptoms. Chemotherapy may help ease symptoms of cancer by killing some of the cancer cells. Healthcare professionals call this palliative chemotherapy.

Chemotherapy for conditions other than cancer

Some chemotherapy medicines have proved useful in treating other conditions, such as:

• Bone marrow conditions. Conditions that affect the bone marrow and blood cells may be treated with a bone marrow transplant, also called a stem cell transplant. Chemotherapy is often used to prepare for a bone marrow transplant.
• Immune system conditions. Lower doses of chemotherapy medicines can help control an overactive immune system in certain conditions, such as lupus and rheumatoid arthritis.

The risks and side effects of chemotherapy medicines can be serious. Each medicine has different side effects, and not every medicine causes every side effect. Talk with your healthcare professional about the side effects of the particular medicines you'll receive.

Side effects that occur during chemotherapy treatment

Common side effects of chemotherapy medicines include:

• Nausea.
• Vomiting.
• Diarrhea.
• Hair loss.
• Loss of appetite.
• Fatigue.
• Problems thinking clearly, which is sometimes called chemo brain.
• Fever.
• Mouth sores.
• Pain.
• Constipation.
• Easy bruising.
• Bleeding.

Many of these side effects can be prevented or treated. Most side effects go away after treatment ends.

Long-lasting and late-developing side effects

Chemotherapy medicines also can cause side effects that don't appear until months or years after treatment. Each chemotherapy medicine can have different possible late side effects, including:

• Damage to lung tissue.
• Damage to the heart.
• Infertility.
• Damage to the kidneys.
• Nerve damage, called peripheral neuropathy.
• Risk of a second cancer.

Ask your healthcare professional if you have a risk of any late side effects. Ask what symptoms you should watch for after treatment ends.

How you prepare for chemotherapy depends on which medicines you'll receive and how the medicines are given. Your healthcare team will likely tell you specific instructions to prepare for your chemotherapy treatments. You may need to:

Have a device placed

If you'll be receiving your chemotherapy as an infusion into a vein, your healthcare professional may recommend a device to help with this. Common devices include catheters, ports and pumps. A healthcare professional can give you chemotherapy medicines through the device.

Have tests to make sure your body is ready

Blood tests to check kidney and liver functions and heart tests to check for heart health can help make sure your body is ready to start chemotherapy. If there's a problem, your healthcare professional may suggest waiting to start treatment or choose a different chemotherapy medicine and dosage that's safer for you.

See your dentist

Your healthcare professional may recommend that a dentist check your teeth for signs of infection. Treating existing infections may lower the risk of problems during chemotherapy treatment, since some chemotherapy may lower your body's ability to fight infections.

Plan ahead for side effects

Ask your healthcare professional what side effects to expect during and after chemotherapy and try to find ways to lower them. For instance, if your chemotherapy treatment will cause infertility, you may wish to consider your options for preserving your sperm or eggs for future use. If your chemotherapy could cause hair loss, you may wish to consider planning for a head covering or trying scalp cooling.

Make arrangements for help at home and at work

Most chemotherapy treatments are given in an outpatient clinic, which means you don't need to stay in the hospital during treatment. Most people are able to continue working and doing their usual activities during chemotherapy. Your healthcare professional can tell you in general how much the chemotherapy may affect your usual activities, but it's hard to predict exactly how you'll feel.

Ask your healthcare professional if you'll need time off work or help around your home after treatment. Ask your healthcare team for the details of your chemotherapy treatments so that you can make arrangements for work, children, pets or other commitments.

Prepare for your first treatment

Ask your healthcare professional how to prepare for chemotherapy. It may be helpful to arrive for your first treatment well rested. You might wish to eat a light meal beforehand in case your chemotherapy medicines cause nausea.

Your healthcare professional may ask you to have someone drive you to your first treatment. Most people can drive themselves to and from chemotherapy sessions. But the first time you may find that the medicines make you sleepy or cause other side effects that make driving hard.

Determining which chemotherapy drugs you'll receive

Your healthcare professional chooses which chemotherapy medicines you'll receive based on several factors, including:

• Type of cancer.
• Stage of cancer.
• Overall health.
• Previous cancer treatments.
• Your goals and preferences.

Discuss your treatment options with your healthcare professional. Together you can decide what's right for you.

How chemotherapy medicines are given

Chemotherapy medicines can be given in different ways, including:

• Chemotherapy infusions. Chemotherapy is most often given as an infusion into a vein. The medicines can be given by inserting a tube with a needle into a vein in your arm or into a device in a vein in your chest.
• Chemotherapy pills. Some chemotherapy medicines can be taken in pill or capsule form.
• Chemotherapy shots. Chemotherapy medicines can be injected with a needle, just as you would receive a shot.
• Chemotherapy creams. Creams or gels containing chemotherapy medicines can be applied to the skin to treat certain types of skin cancer.
• Chemotherapy medicines used to treat one area of the body. Chemotherapy medicines can be given directly to one area of the body. For instance, chemotherapy medicines can be given directly in the abdomen, chest cavity or central nervous system. Chemotherapy also can be given through the urethra into the bladder.
• Chemotherapy given directly to the cancer cells. Chemotherapy can be given directly to the cancer or, after surgery, where the cancer once was. As an example, thin disk-shaped wafers containing chemotherapy medicines can be placed near a cancer during surgery. The wafers break down over time, releasing chemotherapy medicines. A healthcare professional also may inject chemotherapy medicines into a vein or artery that directly feeds a cancer.

How often you receive chemotherapy treatments

Your healthcare professional determines how often you'll receive chemotherapy treatments based on what medicines you'll get, your cancer type and how well your body recovers after each treatment. Chemotherapy treatment schedules vary. Chemotherapy treatment can be continuous, or it may switch between periods of treatment and periods of rest to let you recover.

Where you receive chemotherapy treatments

Where you'll get your chemotherapy treatments depends on your situation. Chemotherapy treatments can be given:

• In an outpatient chemotherapy unit.
• In a healthcare professional's office.
• In the hospital.
• At home, such as when taking chemotherapy pills.

Ask your healthcare professional when you can expect to know the results of your chemotherapy. You'll meet with your healthcare team regularly during treatment. Your care team may ask about any side effects you're having, since many can be controlled.

Depending on your situation, you also may have scans and other tests to monitor your cancer during chemotherapy treatment. These tests can give your healthcare team an idea of how your cancer is responding.