Although these cancer symptoms listed can have other meanings, it's important to be aware of them and take precautions if you feel you're at risk for developing cancer.

1. Bleeding in the gums

This can come from gingivitis, which is inflammation of the gums caused by poor hygiene. However, it can also indicate Leukemia, a type of blood cancer that causes white blood cells to increase in a disordered way. One symptom of Leukemia is easy bruising and bleeding which can occur in the mouth, according to the Cleveland Clinic. Gingivitis is uncommon in children, so if your child has excessive bleeding in the gums you may want to consult a doctor.

2. Dark lines under the fingernail

MD Health outlines why dark lines under your nails should be checked by a doctor as soon as you notice them - this symptom can be from melanoma, a dangerous and deadly type of skin cancer.

3. Dysphagia (difficulty swallowing)

There's a chance you could have esophageal cancer if dysphagia occurs over a long period of time. Difficulty swallowing usually starts out mild, then gets more severe - people with this symptom may adapt their eating habits (taking smaller bites, eating soft foods that are easy to swallow, etc) which only lets the cancer grow unchecked. The American Cancer Society urges individuals who are exhibiting this symptom to see a doctor.

4. Constant stomach pain

It could be food poisoning, but it could also be colon cancer says the American Cancer Society. Blood in the stool or prolonged change in bowel habits (along with fatigue and unintentional weight loss) also signal the need for a visit to your doctor.

5. Shortness of breath

This is a common symptom of many non-threatening ailments (like asthma) but it can also indicate lung cancer. This type of cancer presents itself differently depending on what stage it's in, but some symptoms are manifested early on. Visit a doctor and get your questions answered, especially if you smoke.

6. A sore throat

Feeling pain while chewing or moving your tongue, having a chronic sore throat and swelling inside your mouth could mean mouth cancer, according to WebMD.

7. Bone pain at night

This occurs particularly in children and adolescents. It can be a sign of influenza or other health problems, but it can also be bone cancer. The Cancer Center warns that early on, the pain may only occur at night (or when you are active) but as the cancer develops, the pain may become more persistent.

8. Dark urine

This can also be a sign of kidney or urinary infection (and also severe dehydration) however, it could also be bladder cancer. According to the American Cancer Center, cancer is not typically the first diagnosis when blood is present in the urine, but it can be a sign in some situations.

9. Hoarseness

Professional singers, teachers and speakers could develop hoarseness due to vocal cord injuries, but laryngeal cancer can also cause hoarseness. Other risks of this cancer are smoking, drinking alcohol, a sore throat, difficulty swallowing and weight loss.

10. Lumps in the neck

Lumps can be caused by swollen glands, but these will typically disappear at the end of the infection that caused them. Lumps that form in the thyroid, however, should be checked by a doctor. It can be cancer, especially if the patient shows tiredness, hoarseness, pain in the neck, a frequent cough and trouble swallowing.

Determining if you have cancer includes a lot more investigating than just noticing these symptoms. Before you panic, consider your family history and seek medical advice. It's good to be aware of symptoms and self-exams are fundamental in catching cancer early when it's easier to treat.

This article has been translated and adapted from the original, "10 sintomas de câncer que você desconhece." It was originally published on familia.com.br.