Health anxiety, formerly known as hypochondria, is a mental disorder , excessively worrying about catching any serious physical illness. Even though you may have no physical symptoms in your body, you still think that you are seriously affected with any physical issues, such as heart disease or cancer or any other illness whether you might experience in the past (not severely) or see others experienced. This kind of experience leads them to fear of catching any serious illness or you connect any physical symptoms to serious illness. As you have doubt on having any illness, you constantly worry about your health and keep on checking those physical symptoms on the internet. This behaviour leads to too much of anxiety about health that would be affected with any illness. If you have no serious physical symptoms, but still worrying about your health condition as if you are affected with something serious illness, that must be health anxiety. If this gets treated at the right time, you can prevent its intensity.