Whenever there is a heatwave, such as the one where having a moment, there is always an increase in the number of referrals to my clinic. I would like to comment on some of the reasons for this.

• Sunlight & reflected glare; One of the commonest reasons for increased headache/migraine frequency in summer. Wearing a brimmed hat/baseball cap to shield the eyes from direct sun and a pair of effective sunglasses (making sure their dark enough and of decent quality) are obvious precautions, not to mention keeping to the shade when possible.
Less obvious but also important is reflected light on computer screens, desks
and other surfaces. Use of blinds/curtains can clearly help as can repositioning office
& home furniture.
N.B; there is a brand of sunglasses called `Migralens` (http://www.migralens.com/) which are designed specifically for migraine sufferers which specifically cut out the type of light thought to trigger migraines.

• Dehydration; This is a common cause of headaches in summer. Most people underestimate the extra fluids they need to drink during hot weather especially if taking even gentle exercise.
Exact amounts are difficult to give as it varies with age, activity levels and the environment, but here are some guidelines;
In `normal` weather; Men should drink at least 3 litres/5 pints (about 13 cups) per day. Women- at least 2.2 litres/4 pints (about 9 cups)per day.
In `hot` weather these amounts should be increased by a minimum 1.5 to 2 litres, ie an extra 2-3 pints every day that it is hot. This needs to be even more if exercising, where you may be losing as much as 2 litres per hour as perspiration!!

Note that thirst can be a relatively late sign of dehydration, so drink before you become thirsty! And remember the extra fluid should not be taken in the form of drinks which contain caffeine (coffee, tea & certain soft drinks -always check the label)

Whilst on the subject of drinking it is worth noting that in the hot weather people’s consumption of alcohol also often increases. Needless to say if, like many people, alcohol is one of your triggers this would cause an increase in headaches/migraine.

• Mineral losses; Linked to fluid loss/ dehydration is loss of minerals (electrolytes) leading to changes in concentration ratios between certain important body chemicals. In some people this might increase the tendency to headaches/migraines. Therefore it may be worth taking extra mineral supplements such as dioralyte during particularly hot weather.

• Heat and humidity; Clearly difficult to influence, but the judicious use of fans/dehumidifiers/portable air conditioning units can help.

• Sleep disturbance; In my opinion this can be a very important factor in `heatwave headaches`. We all know it is hard to sleep when it is hot at night and the sleep we do get is often disturbed and therefore of poor quality. Again there’s little one can do about this apart from using fans etc as mentioned above. However if you notice you are waking earlier it may also be due to the increased morning light in which case the fitting of `blackout` curtains /blinds is advisable.

• Missing meals/ change of diet; Most people eat less when it is hot, perhaps even skipping meals, this can lead to low blood sugar levels which ( as discussed in another blog below ) is often a factor in causing headaches/migraine. So try to eat regularly despite the heat.

• Hay fever ; Generally this tends to be worse in the spring and summer and occasionally it will trigger/aggravate headaches if originating in the sinuses( see earlier blog below for info on sinus headaches)

So if you are one of those people whose headaches seem worsen as soon as the Bar-B-Q weather arrives, one or more of the above could be the cause. Try making a few changes as mentioned and see if it helps.


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