8. Persistent headache
For the most part, headaches are benign and could be caused by several conditions, including migraines, tension headaches, and infections.
However, and for a small subset of patients, a persistent headache that’s constantly worsening in severity may indicate the growth of a tumor inside the skull.
7. Frequent Fevers or Infections
In most cases, fever is a sign that your body fights an infection. However, if it’s a prolonged or persistent one, it might indicate a cancerous condition, like lymphoma.
Also, the cancer of the blood cells, leukemia, can cause signs such as fever, frequent infections, aches, fatigue, and other flu-related signs.