Cancer and other serious diseases tend to have better outcomes when treated early. According to data from the National Academies of Medicine published by The Washington Post, 12 million Americans receive a late or missed diagnosis of a life-threatening illness every year, with diagnostic errors contributing to about 10% of patient deaths.

Seek medical help right away or get a second opinion if you notice these possible cancer symptoms.

Unexplained weight loss

If your diet or exercise habits have not changed but you lost more than 10 pounds, seek medical attention. According to the American Cancer Society, this symptom may signify lung, stomach, pancreatic or esophageal cancer.

Breast changes

Women should be aware of any unusual texture that develops in the breast tissue. Regularly check for lumps and visually inspect the breasts for dimpling, puckering, nipple inversion and scaly or red patches. See a doctor if you notice any of these signs or experience unusual nipple discharge.

Blood in the stool

Too often, individuals dismiss the appearance of blood in bowel movements as hemorrhoids. While you may notice bright red blood as a result of hemorrhoids, any change in stool should cause concern. You should seek medical help immediately if you notice dark red or black blood, which could signify colon cancer.

Extreme fatigue

This can be one of the toughest disease symptoms to pin down because it can have so many potential causes, including difficult-to-diagnose conditions such as fibromyalgia. If you constantly feel tired to the point where you have trouble completing your usual activities, seek medical advice.

Abnormal vaginal bleeding

The MD Anderson Cancer Center reports that in 90% of endometrial cancer cases, women experienced bleeding after menopause or other irregular bleeding. Women who are still menstruating should consult a doctor if they notice bleeding after sex or between monthly periods. Unusually heavy bleeding may also be a sign.

Because patients spend limited time with the doctor during a typical visit, you must advocate for your own health when you notice troublesome symptoms. When a provider fails to make a diagnosis, it could impact your potential health outcomes.