Morbidity basically refers to the state of being morbid. Morbid, in turn, refers to the state of being characterized by unwholesome thoughts or feelings, especially regarding death or disease. A person who is morbid is generally considered to have an unusual interest in death or unpleasant events. Any object that is considered to be morbid usually means that it inspires thoughts of death or illness in people.
Morbidity can refer to departure from a state of physical or psychological well-being. A person who is morbid is not generally considered to be healthy, either physically or mentally. A terminally ill patient may be morbid, as their thoughts may be preoccupied with death, especially their own. A person who has lost a dear one may be morbid, as their thought may be filled with their loved one’s death. Additionally, a person who is neither dieing nor lost someone, but is still filled with morbid thoughts of illness and death may be mentally ill if they keep thinking about death.
In science and pathology, morbidity refers to the rate of illness or disease. The higher the chances of a disease occurring means that it has a higher morbidity. Basically, a disease with a high morbidity means that in a group of people that is a higher risk of that disease occurring, and hence steps should be taken to reduce the illness.