What to watch for: Losing 10 pounds or 5% of your body weight without trying, over 6-12 months.

Why it happens: Cancer cells compete for nutrients, and some cancers alter metabolism.

Common cancers linked: Pancreatic, lung, stomach, esophageal.

When to worry: If you haven’t changed your diet or exercise routine.

2. Persistent Fatigue

What to watch for: Exhaustion that doesn’t improve with rest. Sleep doesn’t fix it. Coffee doesn’t touch it.

Why it happens: Blood loss, metabolic changes, or the body’s constant effort to fight something.

When to worry: If rest doesn’t restore you—for weeks.

3. Unexplained Pain

What to watch for: Pain that persists without injury. A headache that won’t quit. Back pain that doesn’t respond to rest. Pain that wakes you at night.

When to worry: Persistent, unexplained pain—especially if it’s new and doesn’t go away.

4. Persistent Cough or Hoarseness

What to watch for: A cough that lingers for weeks. Hoarseness that doesn’t improve. Coughing up blood (even a little).

When to worry: If you’re a smoker or former smoker, this deserves special attention. But anyone with a persistent cough should be evaluated.

5. Changes in Bowel Habits

What to watch for: