Chemotherapy: How It Works and How You'll Feel

Unlike radiation or surgery, which target specific areas, chemo can work throughout your body. It kills cancer cells, but it can also affect some fast-growing healthy cells, like those of the skin, hair, intestines, mouth, and bone marrow. That’s what causes some of the side effects from the treatment.

Is chemotherapy painful?

Chemotherapy usually isn’t painful, especially if you get it as a pill or cream (for skin cancer).

If you get it as a shot, you might notice the needle prick. Some people feel a mild burning when the drugs start to flow, but this goes away quickly.

Immunotherapy. This treatment uses drugs that strengthen your immune system so it can better fight the cancer.

Biological therapy. Living material in the form of bacteria, vaccines, or antibodies are carefully introduced to kill cancer cells.

Chemotherapy may be used to:

• Shrink a tumor before radiation or surgery (neoadjuvant chemotherapy)
• Destroy any remaining cancer cells after surgery or radiation (adjuvant chemotherapy)
• Make other therapies (biological or radiation) more effective
• Destroy cancer cells that return or spread to other parts of your body

Chemotherapy isn’t just used for cancer. It also can help treat autoimmune disorders and prepare people for bone marrow transplants.

Here are some ways to get ready for chemotherapy:

Talk to your doctor. Ask them what to expect. This can help you mentally prepare and make plans. For example, you could bring a book with you during long treatments or ask about medications to manage certain side effects. Your doctor also can suggest resources and support groups.

Get medical tests and imaging done. Your doctor might suggest some tests to make sure your body can handle chemotherapy. They can use the test results to pick a drug and dosage that’s safe for you.

Get a medical device implanted if needed. If you’ll be getting intravenous (IV) treatment, you might need a device that can help deliver the chemo drugs. This could be a catheter, port, or pump. A doctor will surgically place this device into a large vein, often in your chest.

Visit your dentist. Chemotherapy lowers your immunity, making you more vulnerable to infection. It’s important to check for any existing tooth infections and treat them before chemotherapy begins.

Make plans for work and home life. Talk to your boss, coworkers, family, and friends about arrangements for when you’re getting treatment. For example, you might take short-term disability, ask to work remotely, or ask a friend to pick up your kids from school.

Call your insurance company. Chemotherapy is usually covered by insurance, but every plan has different rules. Don’t be afraid to double-check information and ask for help. Some companies offer patient assistance programs. 

Consider side effects and how to deal with them. Talk to your doctor about possible side effects and if there are ways to prevent or treat them. You might not be able to avoid certain side effects, but you can make a plan for them. For example, if chemotherapy will cause hair loss, you can start looking into wigs, scarves, or head wraps. If it will cause infertility, consider freezing your sperm or eggs. If it will make your skin more sensitive, start buying lotions, makeup, and sunscreen designed for sensitive skin.

For your first day of treatment, you should try to get a good night’s sleep and eat a light meal. Chemotherapy might make you nauseous or sleepy. So, it’s probably a good idea to ask someone to drive you. They also can be a source of moral support.

After the first session, you’ll have a better idea about what to eat and whether you can drive yourself to future appointments.

Pills. You can swallow a pill, capsule, or liquid.

Intra-arterial. The drugs go directly into the artery that is feeding the cancer, through a needle, or soft, thin tube (catheter). The drugs can also go into veins.

Intraperitoneal. The drugs are delivered to the peritoneal cavity, which contains organs such as your liver, intestines, stomach, and ovaries. It is done during surgery or through a tube with a special port that is put in by your doctor.

Intrapleural. This is when chemotherapy is delivered directly to your chest.

Intrathecal. For this type of chemotherapy, your doctor uses a needle or long-term catheter and port to inject medicine into the cerebrospinal fluid. This fluid surrounds your spinal cord and brain. Intrathecal chemotherapy is a good option for some brain cancers.

Intravesical. This type of chemotherapy is delivered to the bladder through the urethra. The urethra is the tube through which pee comes out. A doctor will thread a soft, thin catheter through your urethra, leave it in for a few hours during each treatment session, and then take it out.

Intramuscular. This is when the doctor uses a needle to inject chemo drugs into your muscles.

Intralesional. Depending on where the tumor is, your doctor might be able to inject drugs directly into it.

Surgical. In some cases, chemotherapy can be delivered directly to the tumor. During surgery, the doctor will put a thin wafer near the tumor. The wafer contains chemotherapy drugs and releases them as it breaks down. It also can be put in the empty spot where a cancer was surgically removed.

Depending on the type of chemotherapy you get, treatment could take place in:

• Your home (pills and creams)
• Your doctor’s office
• A specialized clinic
• An outpatient hospital infusion center
• A hospital

But often, you’ll need other devices to make the process run more smoothly. The most common device is a soft, thin tube called catheter. If you get chemo through a catheter, the doctor doesn’t put the needle directly into your skin. Instead, they’ll thread one end of this tube into a large vein, often in your chest area. The other end stays outside your body. The doctor will use a needle to deliver chemotherapy and other drugs into the outer end of the tube. They can also use this tube to draw blood. Getting chemotherapy through a catheter takes a few minutes to a few hours.

If you get chemo through a catheter, you also might need a device called a port. This is a small disc that a surgeon connects to the catheter and places under your skin. A nurse may insert a needle into your port to give you chemotherapy drugs or draw blood. The needle can be left in place for treatments that last more than a day.

Sometimes, you’ll have a pump attached to your catheter or port. This device controls the flow of chemotherapy drugs (how fast they get into your body). You may carry this pump with you, or a surgeon may place it under your skin.

Long-term catheters and ports are good options when you need several chemotherapy treatments and don’t want to get repeated needle pokes. They also can deliver other medications, such as antibiotics and anti-nausea medicines. The doctor will place them into your vein and under your skin during a minor surgery.

Some common side effects are:

• Hair loss
• Nausea and vomiting
• Diarrhea
• Constipation
• Not feeling hungry
• Weight loss
• Mouth sores
• Fatigue
• Mood changes
• Fever
• Numbness, tingling, or pain
• Dry skin
• Changes in skin and nail color
• Kidney and bladder problems
• Libido changes
• Easy bruising and bleeding
• Anemia (low levels of red blood cells)
• Neutropenia
• Infection

Doctors can help prevent or treat many of these side effects. If necessary, they can even adjust your treatment to avoid certain side effects. Side effects usually go away soon after chemotherapy ends.

Chemotherapy and hair loss

Your hair grows out of tiny skin structures called hair follicles. Chemotherapy damages these follicles, causing hair to fall out. Depending on the drug, you might have hair loss or thinning just on your head, or also on your eyebrows, eyelashes, armpits, arm and leg hair, and pubic hair. But it affects everyone differently. Even for two people taking the same drug, one might have hair loss and the other won’t. 

Hair loss usually starts 1-3 weeks into treatment and becomes more noticeable at 1-2 months. It may be quick or slow. Clumps might come out when you wash or brush your hair.

Hair loss can be very upsetting. It might help to remember that it will grow back. In fact, it will probably start growing back before treatment is even finished. In the meantime, you can wear fashionable wigs, scarves, or head wraps, or if you prefer, you can shave your head.

Chemotherapy and constipation

Constipation is when you have trouble pooping. It happens when poop stays in your large intestine (colon) for a long time. This allows the colon to absorb more water from your poop than usual, making your poop hard.

Tell your doctor if you don’t poop for 3 days, see blood in your poop, or have stomach pain or vomiting. Call 911 if you have bleeding from your rectum or severe stomach pain that won’t go away.

Chemotherapy and diarrhea

Diarrhea is when you have frequent, watery poops. You might also have stomach pain or cramps. Some cancers (especially pancreas, gastric, and colorectal), chemotherapy drugs (especially 5-fluorouracil, capecitabine, and irinotecan), and other cancer treatments can cause diarrhea. You might get diarrhea a few days after starting chemo.

If you have diarrhea, drink plenty of fluids to avoid dehydration. When ready, eat foods such as bananas, applesauce, toast, Jell-O, broth, and Popsicles. Ask your doctor if you should take any medications.

Talk to your doctor if the diarrhea lasts over 24 hours, you can’t keep liquids down for over 24 hours, you see blood in your poop, or have a fever. Call 911 if you have intense stomach pain or rectal bleeding that won’t go away, or if you can’t pee or eat for 24 hours.

Chemotherapy and mouth sores

Some kinds of chemotherapy can damage cells in the mouth, throat, and gastrointestinal system. This can lead to cuts or sores in the mouth, sometimes extending into the throat and beyond. They might be red or have small white patches. Some may bleed, leak pus, or be covered in a white or yellow film. You also may notice acid reflux, extra mucus in your mouth, or a dry or burning feeling while you eat. These sores can be painful and make it difficult to eat or swallow.

Mouth sores often appear 1-2 weeks after starting treatment and go away 2-4 weeks after treatment ends.

Call your doctor if you have:

• Cuts or sores in the mouth
• Bleeding gums
• White patches on the tongue or in the mouth
• Fever
• Difficulty eating or taking medicine

Chemotherapy and skin rash

Chemotherapy and other cancer treatments can cause changes in the skin. Some people may have dry skin or changes in skin color.

Rashes are also common. They can form on the scalp, face, neck, upper back, chest, and other body parts. They might be itchy or painful, or they might cause burning and stinging.

Keep in mind that a skin rash from chemo is not the same as a rash caused by an allergic reaction to chemo. Talk to your doctor about all skin rashes. They can help you find the cause and treat it.

If you have a rash, keep it clean with warm water and soap, then pat it dry. Stay out of the sun when possible, and wear sunscreen and a hat. Ask your doctor about soap, lotions, or medications that might help.

Call your doctor if:

• You’ve tried creams or lotions, but the rash has gotten worse.
• The rash itches for over 48 hours.
• The rash is bleeding or leaking smelly fluids.
• The rash has blisters, crusts, or bright red skin.
• The itchiness or discomfort keeps you awake at night.
• Your skin turns yellow.
• You have brown pee.

Chemotherapy and nails

Cancer treatment can affect nails in many different ways. These changes might affect one or many nails, start soon or a long time after treatment, and be temporary or permanent.

Common changes include:

Painful or delicate nailbeds. Red, swollen, or inflamed nailbeds can be caused by doxorubicin, docetaxel, paclitaxel, and nab-paclitaxel. In some cases, this could lead to painful infections.

Nail plate lifting away from skin or falling off. Dacarbazine, daunorubicin, and mitoxantrone can cause your nail plate to separate from the skin and possibly fall off. This change is usually temporary. Be careful to avoid infections in the exposed area.

You can protect your nails by:

• Wearing a prescription nail polish
• Taking a biotin supplement (with your doctor’s approval)
• Trimming your nails regularly
• Keeping them clean
• Wearing gloves when washing dishes, gardening, or cleaning
• Wearing loose-fitting shoes

Tell your doctor about any changes in your nails. In some cases, you might need medication or surgery.

Chemo brain

Chemotherapy and other cancer treatments can cause problems with memory, thinking, and focus. You might have trouble remembering dates, finding words, or multitasking. This is sometimes called “chemo brain” or “brain fog.”

Brain fog might start before, during, or after chemotherapy. Scientists aren’t sure why it happens. Other health issues may also play a role. But it usually gets better over time.

Meanwhile, some things can relieve brain fog or manage it:

• Exercise
• Meditation
• Yoga, tai chi, or qi gong
• Some types of therapy
• Routines
• Puzzles and word games
• Rest

Tell others how you are feeling. Family, friends, and coworkers are often understanding and can help support you. Your doctor can suggest therapies and other coping strategies.

When to worry

Some side effects can be signs of bigger problems. Call your doctor right away if you have:

• A fever of 100.5 F or higher 
• Unexplained bleeding or bruising
• Rash
• Swollen mouth or throat
• Severe itchiness
• Trouble swallowing
• Trouble breathing
• Strong chills
• Pain or soreness where the needle or catheter enters your body
• Unusual pain
• Severe headaches 
• Diarrhea or vomiting that doesn’t go away
• Blood in your pee or poop

Take care of your hair and scalp. Ask your doctor if a cooling cap might safely lower your chances of hair loss. Be gentle with your hair and scalp. Avoid brushing, pulling, or curling it during treatment. You might want to wear a hair net at night or use a satin pillowcase to minimize hair loss. Protect your scalp with sunscreen in nice weather and a hat in cold weather.

Try new styles of headwear. If you have hair loss, it’s important to find a style that makes you feel comfortable and confident. You might want to buy a wig that matches your current hairdo, create a collection of fashionable head wraps and scarves, or shave your head for a bold statement. Research different styles and materials (some may vary in feel, cost, adjustability, and maintenance requirements) to find the option that’s right for you. The most important thing is that you feel good about yourself.

Can I work during chemo?

Chemo affects everyone differently. It’s hard to know how you’ll feel ahead of time, but your doctor can give you an idea of what you can expect. Some people might be able to continue their daily activities, but others might need to take time off work. You can also talk with your boss about working remotely or having flexible hours.

Remember that there are laws to protect you. The Americans With Disabilities Act gives you the right to ask for reasonable accommodations such as getting regular breaks, modifying your job duties, and providing certain equipment. In addition, the Family and Medical Leave Act can protect your job if you need to take time off while you get treatment.

Chemotherapy costs include things such as physician and nurse labor, lab testing and imaging, overhead, and more. Because of all these different factors, the cost can vary a lot. Estimates are as high as $48,000.

But insurance will usually help pay for chemotherapy. The exact amount depends on what plan you have. You might have to spend a certain amount of money (called a deductible) before insurance starts paying for treatment. Plus, you might have to pay a set copay at each visit, or you might pay a certain percentage of the total cost. Make sure to read your health insurance policy to find out exactly what it will and won’t pay for. 

For example, Medicare Part A only covers chemotherapy that’s given during an inpatient hospital stay. If you get it as an outpatient, you’ll need to use Medicare Part B. As soon as you meet your deductible, Medicare Part B will start paying for most of the costs. You will still need to pay a set copayment at each visit (if you’re getting chemo at an outpatient hospital clinic) or 20% of the bill (if you’re getting chemo at a doctor’s office or freestanding clinic). In addition, you may still need to pay for the drug itself. Medicare Part D covers some chemotherapy drugs, but not all.

When in doubt, call your insurance company to ask questions. Do this before starting treatment to avoid any unpleasant surprises. Your doctor might need to write a letter explaining why you need a certain treatment.

If you have trouble paying your bills, you can talk to your doctor’s billing team or hospital financial counselor. You might be able to get:

• Lower rates
• Payment plans (you pay the bill a little bit at a time)
• Patient assistance

Some charities and organizations can help pay for treatment and other needs. CancerCare (and its aid search tool, A Helping Hand), the Cancer Financial Assistance Coalition, and the National Cancer Institute support services directory are good places to start.