Headache :

It is a common exerience by most of the people sometime in their life. It is one of the most important causes of working hours lost to an illness. When it is very frequent or very severe it needs medical attention to evaluate and  manage it. The causes can range from diseases of relatively mild nature (like sinusitis) to severe one's (like brain tumor, bleeding in the brain). 


http://patients.aan.com/disorders/index.cfm?event=view&disorder_id=936


Stroke :

It is a catastrophic event that affects the blood supply of the brain and leaves a person with severe deficits within a period of minutes to hours. With the rise in hypertension, diabetes mellitus and heart problems, the risk of stroke has considerably increased in population. Timely medical attention and treatment is vital in the prevention of long term disabiity following a stroke.


http://patients.aan.com/disorders/index.cfm?event=view&disorder_id=1072


Convulsion/ Seizure/ Fits/ Epilepsy :

Only one who has seen or experienced a seizure can tell, how dramatic and frightening event it is. With modern medications most of the atients are able to live their lives normally and productively even with epilepsy. For a few unfortunate patients, whose seizures are uncontrolled with routine medication, advanced surgical options are available to control seizures.

Dizziness/ Giddiness/ Vertigo :

A variety of other terms may be used by different patients and similarly there is a long list of causes which can cause it. The most important thing is to correctly identify the cause and treat it.

Dementia:

It is commonly a disease of the elderly which results in compromise of the intellectual functions involving various domains like memory, language, thinking, calculation etc. Apart from distress to the patient, the care givers and relatives are equally or may be more burdened in a family having patient with dementia.