A balance symptom that is characterized by an inability to stay upright and move confidently. Loss of balance may be due to problems in the inner ear, the brain, or the heart. Aging, infections, head injury, certain medicines, and problems with blood circulation may also cause balance problems. [ url:https://www.nidcd.nih.gov/health/balance-disorders url:https://medlineplus.gov/balanceproblems.html ]