Definition:
Headache is a term used to describe aching or pain that occurs in one or more areas of the head, face, mouth, or neck.
Headache can be chronic, recurrent, or occasional. The pain can be mild or severe enough to disrupt daily activities.
Headaches are a characteristic symptom of many conditions and management requires accurate determination of the
aetiology.
Types of headaches include:
Cluster headaches
Eyestrain headaches


Exertional headaches
Hormonal headaches
Metabolic headaches
Sinus headaches
Trauma headaches
Tension headaches
Toxic headaches
Vascular headaches

Risk Factors:
There are numerous causative factors and risk factors that can contribute to the incidence of headaches. Some of the most common ones include the following:
Improper eyeglass prescription
Poor lighting
Eyestrain
Lack of exercise
Lack of sleep
Magnesium-deficient diet
Alcohol
Poor posture and muscular tension
Infections and fever
Alcoholism
Uraemia
Drug use
Toxic burden
Heavy metal toxicity
Carbon monoxide poisoning
Heroin use
Hormonal imbalances (i.e., oestrogen imbalance)
Hypoglycaemia
Family history of tension headache
Chronic stress or anxiety
Depression
Irritability
Excessive caffeine intake
Caffeine withdrawal
Overwork syndrome
Temporomandibular joint (TMJ) dysfunction (often caused by grinding teeth)
Cervical spine mechanical problems
Hypothyroidism
Low adrenal function
Dehydration
Artificial sweeteners (up to 14% incidence in aspartame users)

Symptoms & Signs
Common signs and symptoms of headaches include:
a. Pain –described as feeling as though one's head were being squeezed in a vice or constricted by a tight hatband , as a pulsating pain, or as a dull, generalised ache.
b. Insomnia
c. Tight, sore muscles in neck and shoulders
d. Emotional stress
e. Mental "fuzziness" and inability to concentrate
f. Mood changes
g. Fatigue
h. Nasal stuffiness
i. Tearing of the eyes
l. Nausea and/or vomiting