Your body is constantly sending signals

Some are obvious—a fever, a cough, pain, itching, dizziness, or fatigue. Others are more subtle: changes in sleep, mood, appetite, energy, concentration, or simply the feeling that something isn't quite right.

These signals are not random. They are part of the body's ongoing effort to monitor itself, adapt to changing conditions, and maintain balance.

But sometimes body signals can fool you.

A person may feel pain in the left arm during a heart attack when the problem is actually in the chest. An amputated limb may continue to hurt years after it is gone. Motion sickness can occur when the eyes and inner ear disagree about movement.

What is the body trying to accomplish when it sends these signals? And why do those messages sometimes seem confusing?

In this section, we'll explore symptoms, sensations, lab values, and other clues that can help us better understand how the body works.