What to do when a diagnosis is elusive

Hard-to-explain symptoms are remarkably common. Here’s how to navigate finding an answer.

Nearly every week, primary care physician Dr. Daniel Sands examines a patient whose vague but troubling symptoms — such as fatigue, headaches, dizziness, or body aches — don’t readily point toward a specific condition.

Even after a series of tests, a clear diagnosis remains elusive in a striking number of such cases. "Broadly speaking, this happens quite often," says Dr. Sands, who’s based at Harvard-affiliated Beth Israel Deaconess Medical Center. "I’ll see a patient whose symptoms don’t fit any diagnosis or framework."