I'm physically fit but always tired, what could be wrong?

Go see ur Family Doc: If you're fit but always tired, we need to check for depression, hypothyroidism & anemia among top 3. Depending upon collar size, we might screen for sleep apnea, too, especially if you snore or have difficulty staying awake during day. We also need to review your medication list for side effects. For that matter, bring in your dietary supplements & OTC meds, too. What's your risk for STDs esp HIV