Digestive 
Blood
Cardiovascular
Dermatology
Genitourinary,
Hormones
Infections
Oncology and
Musculo-skeletal
Mental health and
Parasites
Respiratory
Senses
Various
Pain is a sensation triggered by the nervous system. It can be acute or chronic, intermittent or constant. You may feel pain somewhere in the body, such as the back, abdomen or chest or you could feel widespread pain such as muscle pains during a flu.
Acute pain usually results from a disease, inflammation or an injury. The cause of acute pain can usually be diagnosed and treated, as it is limited to a location and a period of time. In some cases, it can become chronic.
Chronic pain is associated with higher rates of depression and anxiety. Sleep disorders and insomnia due to disease that causes pain and even due to the medication may also occur.
