9 cancer symptoms you should never ignore

Symptoms can sometimes be easy to miss. Even seemingly minor things, like a nagging cough or backache, can sometimes point to cancer.

“I tell patients that if there are symptoms that are out of the ordinary or persistent or frequent in nature or extreme in intensity, they should seek attention from their primary provider so they can help decide what the issue is,” says oncologist Elwyn Cabebe, MD, of Good Samaritan Hospital. Read on to learn about nine symptoms of cancer that may go unnoticed.

According to the American Cancer Society (ACS), one of the first signs of cancer may be an unexplained decrease of 10 or more pounds. Some of the weight loss may stem from muscle loss and weakness that happens when the body is trying to fight cancer. Types of cancer that tend to cause unintended weight loss include cancers of the pancreas (an organ that produces substances that help in digestion) and esophagus (the tube that carries food from the mouth to the stomach).

Diarrhea, constipation, change in size of your stool (poop), narrowing of stool—these are all symptoms to have checked out. Another sign is blood in the stool, which may not always be that noticeable. When blood is in the stool, it can appear dark red or blackish in color. While these symptoms may indicate other digestive problems, they may also be early signs of colon cancer, which affects the large intestine.

A fever is often the body's natural response to an infection or illness. And while fevers rarely point to cancer, they are quite common in people with cancer—especially if the cancer has affected the immune system. Healthcare providers (HCPs) aren't quite sure why some cancers cause fevers and others don't; one explanation is that fever is caused by toxins produced by a tumor. Fevers may occur daily or you might go weeks without one. They can also cause night sweats, which is when you sweat heavily during sleep, often sweating through your pajamas or sheets. Fever related to cancer may be an early sign of blood cancer such as leukemia and lymphoma, two different types of cancers that affect white blood cells which help fight off infection or other illnesses.

During cold and flu season, a persistent cough may seem typical, but if you don’t have any other of the usual cold and flu symptoms such as a runny or stuffy nose, you should get it checked out. You should also see your HCP if you've tried to remedy the cough or sore throat but nothing seems to work, particularly if blood accompanies the cough. A long-lasting cough or hoarseness in the throat may be an indicator of lung cancer.

Pain is usually a sign that you need to pay attention to your body, and that can mean a number of things. But pain that doesn't go away after attempting to treat it might signal cancer. For example, headaches that don't go away can be a sign of brain cancer, while consistent back pain may be a sign of cancer of the colon (large intestine), rectum (last several inches of the large intestine) or ovaries (reproductive organs where eggs are stored and released as part of the menstrual cycle).

Blood or discharge from anywhere in the body can be concerning, and this symptom can occur in both early and late stages of cancer. The ACS gives examples of what bleeding or bloody discharge may mean for different areas of the body:

• In the stool: colon or rectal cancer
• In the urine: bladder or kidney cancer
• From the nipples: breast cancer
• From coughing: lung cancer 

According to the ACS, it's not exactly understood what causes the fatigue. But fatigue or extreme exhaustion that doesn't improve with rest is one of the most common cancer symptoms. In colon or stomach cancers, this exhaustion may stem from blood loss that isn't noticeable. Other signs of cancer-related fatigue include feeling too tired to complete everyday activities, trouble concentrating and feeling weak, irritable and upset.

These symptoms most often appear in the mouth or on the skin as a sore that won't heal, which may signify either skin or oral cancer. People who smoke, chew tobacco or drink alcohol in excess are particularly at risk for mouth cancer. Other things to watch for are white patches in the mouth and tongue that have been there for a while. These patches may indicate leukoplakia, a precancerous area that can become mouth cancer if not treated. See your HCP or dentist for treatment options if you notice these signs.

Cancer can sometimes be felt through the skin, such as lumps in the chest area that can indicate breast cancer. The ACS reports that cancerous lumps may also appear in testicles, lymph nodes (small, bean-shaped that filter substance and store white blood cells of the immune system) and within other soft tissues of the body, such as fat, nerves, and tendons. Some breast cancers may also show up as red or thickened skin instead of a lump. If you notice any changes in color, size or shape of a wart, mole or freckle, see your HCP, as this could be a sign of skin cancer and certain other types of cancer.

Some cancers may not cause any symptoms at all, or only when they’re at an advanced stage and may be harder to treat, which is why cancer screening is so crucial. "I think what's most important is to get all the cancer-appropriate screening tests, and that includes colonoscopies [which looks at the inside of the large intestine using a long, flexible tube with a camera and light at the end], mammograms [X-ray of the breast to detect early breast cancer], pap smears [which tests for cervical cancer], etc.," says Dr. Cabebe. In addition to these tests, he recommends making certain lifestyle changes—like quitting smoking or limiting your alcohol intake—to help reduce your risk of cancer.