Your grand father is suffering from stroke
and reduction of, or disruption in, blood flow to the brain is the cause of a stroke.
A stroke is usually defined as two types..
Ischemic (caused by a blockage in an artery
Hemorrhagic (caused by a tear in the artery's wall that produces bleeding into or around the brain)
The consequences of a stroke, the type of functions affected, and the severity, depend on where in the brain it has occurred and the extent of the damage.
Depending on the severity of the symptoms and how much of the body is involved, these impairments can affect the ability to walk, to rise from a chair, to feed oneself, to write or use a computer, to drive, and many other activities.
Many stroke survivors recover functional independence after a stroke, but 25% are left with a minor disability
and 40% experience moderate-to-severe disabilities.
Once your grand father recovers,then he must control all his risk factors like diabetes
,high lipids etc,because chances of recurrence of stroke is highest in next few months.