It is expressed as the systolic pressure (the amount of work the heart has to do to pump the blood around the body) over the diastolic pressure (an indication of the pressure needed to refill the heart). A normal reading is about 140/80.The higher your blood pressure (BP), the more risk there is of heart attack and stroke. This would be potentially fatal underwater, so there are rules that govern diving and blood pressure If a BP exceeds 160/100 then you are barred from diving. But a lot of readings can be artificially high when you rush in to see the doctor - even the process of seeing your GP is enough to raise it, so called "white coat hypertension" So make sure several readings are taken. If it is high and you are desperate to dive, then weight loss, exercise and medication can reduce the pressure and allow you to dive after all.
Some medications are better than others though, so stay away from beta blockers, eg atenolol, as they can affect the lungs whilst diving. Try one of the newer tablets like losartan as they are safer....AN EAR INFECTION?When you descend on a dive, the surrounding water exerts pressure on the body Solids and liquids are fine: they stay the same. Air spaces, though, will contract and need the pressure in them to be increased to be the same as the depth you are at This is called equalization. The main spaces that need to be equalized are the sinuses and the middle ear.
A simple Valsalva movement, like stopping a sneeze half way through, will do this. The problem with a middle-ear infection is that the inflammation will stop air from entering this area, so equalizing becomes impossible. If you dived with this, the remaining air would contract and damage the ear drum and windows into the inner ear where the balance centres are. This would result in a permanent ringing and even deafness.So if you suspect you have an ear infection, see a doctor, start antibiotics if needed, but don't dive until it is fully better.Dr Jules Eden is a Diving Doctor at the London Diving Chamber in St Johns Wood, London (020-7806 4000; ). It started out as a surfing holiday, but our camper van broke down, so we ended up hiring bikes and exploring on two wheels instead. It certainly wasn't as glamorous as subsequent holidays.Best holiday?Rio de Janeiro during the carnival Rio has to be the most glamorous destination ever.
