The word “cancer” can feel scary. But understanding what it is—and what it isn’t—can help take away some of that fear. This article will explain what cancer is, how it starts, and how doctors treat it. We’ll keep things simple and gentle so you can feel more informed and more in control.
What is cancer?
Your body is made up of tiny building blocks called cells. These cells work together to keep you healthy. Old cells die and are replaced by new ones in a careful, orderly way.
Cancer happens when this process goes wrong. Instead of dying when they should, some cells grow out of control. They don’t act like normal cells anymore. These cells can form a lump, called a tumor, or they can spread to other parts of the body.
Not all growths are cancer. Some are benign, which means they won’t spread. But malignant tumors are cancerous, and they may grow quickly and affect other organs if not treated.
How does cancer start?
Cancer often starts when something damages the DNA inside a cell. DNA is like a set of instructions that tells each cell how to work. If these instructions get mixed up, the cell may grow when it shouldn’t. Over time, these damaged cells can form a tumor or move into nearby tissues.
There are many things that can cause this kind of cell damage. These include:
Getting older
Smoking or breathing in smoke
Spending a lot of time in the sun
Certain infections (like HPV)
Being around harmful chemicals
Family history of cancer
Sometimes, cancer starts for no known reason. That’s why regular checkups are important—so doctors can catch problems early, even when you feel fine.
Where can cancer happen?
Cancer can happen almost anywhere in the body. Some of the most common types include:
Breast cancer occurs mostly in women, but men can get it, too
Prostate cancer, common in older men
Lung cancer, often linked to smoking
Colon or rectal cancer, also called colorectal cancer
Skin cancer, often caused by sun exposure
Blood cancers like leukemia or lymphoma
Every kind of cancer acts a little differently. Some grow slowly. Others move fast. Your doctor will look at where the cancer is, how big it is, and whether it has spread to decide the best plan for you.
What are the symptoms?
Cancer doesn’t always cause symptoms at first. That’s why regular preventive screenings recommended by your doctor are so important. These include:
Mammograms
Colonoscopies
Prostate-specific antigen (PSA) tests
Skin examinations
Here are some general signs and symptoms to look out for:
A Lump or Swelling Anywhere in Your Body
A new lump, bump, or swelling—especially in the breast, neck, armpit, or groin—should be checked. Lumps can be painless and slow-growing, so don’t wait for them to hurt before calling your doctor.
Unexplained Weight Loss
Losing weight without changing your diet or activity level—especially more than 10 pounds—can be a sign that your body is working hard to fight something. This may be an early clue, particularly for cancers like pancreatic, stomach, lung, or esophageal.
Feeling Very Tired All the Time
Everyone feels tired sometimes, but cancer-related fatigue is different. It doesn’t get better with rest and may feel like you're dragging through your day. This can be a sign your body is using up energy to fight a growing tumor.
Pain That Doesn’t Go Away
Ongoing pain—like back pain, headaches, or joint pain—could be linked to cancer, especially if it’s new and doesn’t go away with usual treatments. While pain can come from many causes, long-lasting discomfort should be looked into.
Changes in Your Bathroom Habits
New or ongoing constipation, diarrhea, trouble urinating, or blood in your stool or urine may signal problems with the colon, bladder, or kidneys. These are especially important signs to talk about with your doctor.
Changes to Your Skin
Watch for moles that change shape, size, or color. A sore or scab that doesn’t heal after a few weeks can also be a red flag. These may be early signs of skin cancer like melanoma, which is easier to treat when caught early.
Coughing or Hoarseness That Doesn’t Go Away
A persistent cough—especially if it brings up blood—or a hoarse voice that lasts for more than a couple of weeks can be signs of lung, throat, or thyroid cancer. Don’t assume it’s just a lingering cold. It’s worth getting checked out.
These symptoms don’t always mean you have cancer—but they do mean it’s time to talk to your doctor.
How is cancer treated?
If you are diagnosed with cancer, don’t panic. Many types of cancer can be treated—and even cured—especially when found early.
There are several common treatment options:
Surgery to remove the tumor
Radiation therapy uses high-energy rays to kill cancer cells
Chemotherapy uses medicine to stop cancer from growing
Immunotherapy helps your body’s immune system fight cancer
Targeted therapy blocks the specific parts of cancer cells that help them grow
Some people need just one kind of treatment. Others may need a combination. Your doctor will explain the best plan based on your health, the type of cancer, and your goals.
Living With Cancer
Being told you have cancer is never easy. But many people live long, full lives during and after treatment. Cancer care today is more advanced than ever, and doctors have many tools to help.
Here are some tips for living well with cancer:
Stay Active: Even light walking can help you feel better.
Eat Healthy: Nutritious foods support your body and your immune system.
Rest When You Need It: Cancer treatment can make you tired, so don’t push yourself too hard.
Talk About It: Support groups, counselors, and friends can help you feel less alone.
Follow Your Treatment Plan: Stay in touch with your doctor and go to all appointments.
A Message of Hope
Knowledge is power when it comes to cancer. The more you understand, the more confident you can feel about asking questions and making choices that are right for you.
Cancer doesn’t always mean the worst-case scenario. Many people get treatment, recover, and continue enjoying time with family, friends, and favorite activities.
If something doesn’t feel right in your body—or if you’re due for a screening—talk to your doctor. A simple conversation could help you catch a problem early or bring peace of mind.
Sources:
National Cancer Institute: What is Cancer?
Mayo Clinic: Cancer