Who has high Blood Pressure?
Any adult who is over 20 years of age, and who has a Systolic Blood Pressure of equal or more than 140 mm of mercury and a diastolic BP of equal or more than 90 mm of mercury on two separate occasions when recorded in a relaxed sitting position is considered hypertensive.
A Systolic Blood Pressure between 120 to 139 or Diastolic Blood Pressure between 80 to 89 is considered pre-hypertensive and requires to be monitored for hypertension in the future.
Home monitoring of BP
If patient measures the blood pressure at home, it leads to better compliance and smoother control. Blood pressure in the clinic could be falsely high due to emotion (White coat hypertension). Where there is a doubt a 24 hours ambulatory blood pressure monitoring can be done to identify changes of BP throughout the day in different settings.
Salt intake
An important cause of hypertension is the salt intake. Salt is a food preservative known to the mankind for several centuries. The average intake of salt is 10 to 15 grams per day. WHO recommends an intake of only 5 grams per day. Salt is present naturally in food, is added when cooking and is present as a hidden salt in packaged food. Reduction of salt in the diet leads to better control of blood pressure. It is necessary to eat fresh food as far as possible and avoid adding extra salt while eating.
Physical activity
Exercise is very important in helping to reduce Blood Pressure. All forms of isotonic exercises where the muscle tone does not change much, but the length changes ( aerobic exercise, free hand exercise, walking etc) will lower 5 to 10 mm of blood pressure over a period of time. Isometric exercises (weight lifting, resistance training etc) lead to rise in blood pressure.
Bio feedback mechanisms
Yoga, meditation, music therapy etc can lower blood pressure by reducing the output of impulses from the nervous system.
Body weight (BMI, Waist-Hip Ratio, etc.)
Obesity is associated with high blood pressure. Weight reduction lowers the blood pressure.
Drugs
All drug therapy require proper supervision by the physician.There are several groups of drugs available to control blood pressure.
1. Diuretics (like Thiazide)
These drugs remove salt through the kidney leading to drop in Blood Pressure.
Common side effects : Weakness, low potassium.
2. Calcium channel blockers (like Nifedipine, Amlodipine etc)
These drugs block the cellular passage of calcium in the blood vessels and produce dilatation of blood vessels leading to drop in blood pressure.
Common side effects : Swelling of the legs
3. Angiotensin Converting Enzyme (ACE) Inhibitors (like Captopril, Enalapril, Lisinopril etc)
Normally a harmone called Renin is produced in the kidney. This hormone acts on the substance called angiotensinogen and converts it to angiotensin I & II. Angiotensin-II is a powerful constrictor of blood vessels. These drugs, ACE inhibitors act on angiotensin converting enzyme and prevent angiotensin formation.
Common side effects : Cough, High potassium
4. Angiotensin – II blockers (like Losartan, valsartan, irbesartan etc)
These drugs prevent the action of angiotensin-II on the blood vessels.
Common side effects : Cough, High potassium
5. Alpha blockers (like Prazosin etc)
Alpha receptors are present in blood vessels. Stimulating them will produce constriction of blood vessels leading to high blood pressure. These drugs block the alpha receptors leading to drop in blood pressure.
Common side effects : Swelling of the legs.
6. Beta blockers (like Atenolol, Metoprolol etc)
These drugs block beta receptors. Beta receptors are mainly present in heart. Blocking them result in drop in blood pressure and drop in heart rate.
7. Centrally acting drugs (like Clonidine, Reserpine etc)
These drug act in the nervous system centrally resulting in reduced production of certain hormones leading to drop in blood pressure.
Common side effects : Depression.
Do not stop the drugs even if the blood pressure is under good control without the physicians advice.