Why Am I Always Tired? How Internal Medicine Investigates Persistent Fatigue

Feeling tired all the time, even after what should be enough sleep, is one of the most common complaints patients bring in — and one of the trickiest to pin down.

Fatigue Has a Long List of Possible Causes

Thyroid issues, anemia, sleep quality, blood sugar, mental health, and simple overcommitment can all present as persistent fatigue — often more than one at once.

Why Lab Work Usually Comes First

Bloodwork helps rule out or confirm several common causes early, narrowing down where to focus rather than guessing.

When It’s Been Going On for a While

Fatigue that’s lasted weeks or months, rather than a few rough days, is worth a real evaluation rather than pushing through indefinitely.

A Methodical Process, Not a Single Test

Getting to an answer is often a process of ruling things out systematically — which is exactly what internal medicine training is built for.