The loss of motor function on one side of the body is hemiplegia paralysis. This type of paralysis is the result of brain damage like traumatic brain injury, stroke, aneurysm, brain infection, tumors or cancers in the brain, or an injury during childbirth that occurs on the opposite side of the body. For instance, if the left hemisphere of the brain is damaged, a person can suffer right-side hemiplegia, which would impact the right arm and/or leg and possibly the face and torso. Hemiplegia can mean complete paralysis, resulting in the total loss of function and feeling on one side of the body, or partial paralysis, causing a significant loss of sensation and control in the affected area of the body. any type of hemiplegia can negatively impact someone for the rest of their life.

In siddha system this is defined as one of the 80 types of vatha disease pakka vatham, which affects the functions of arms, legs, fingers, tongue, mouth and eyes. The early symptoms that manifest are heaviness of body, constipation, rapid pulse and fainting. In pakka vatham there is sudden fainting followed by paralysis of one side of the body. Sometimes facial deviation and drooping of eye lid may also be present on one side with Loss of speech and dripping of saliva. In some cases numbness in foot and legs with difficulty in walking are present as early symptoms.