Balance is a group effort of the eyes, inner ear, joints, and muscles. They each send signals to the brain about body position and head movement. Then the brain uses this information to achieve balance. When the brain receives conflicting signals, or when there is a problem with blood flow, dizziness or fainting can happen.
Vertigo is the feeling of spinning. It may happen if the brain receives conflicting balance signals. Vertigo is often caused by a problem in the inner ear. Problems include changes in inner ear structures, infection, swelling, or excess fluid. Sometimes vertigo is due to a brain problem, such as migraine.
Dysequilibrium is the feeling of imbalance without a sense of spinning. It may happen if the signal path between the body and brain is disrupted. There are many causes of dysequilibrium, including diabetes, anemia, head injury, and aging.
Syncope is losing consciousness or fainting. The brain needs oxygen-rich blood to function. The heart pumps that blood to the brain. If there is a problem with the heart, blood flow (such as low blood pressure), or blood vessels, faintness may happen.