Hypertension is the gradual development of disease of the arterial walls. This occurs most commonly in the vessels under stress, particularly the arteries of the heart muscle itself, the aorta, the vessels of the brain, and in the vessels of the retina, the sensitive organ at the back of the eye.
Atheroma and subsequent atherosclerosis (arteriosclerosis) can develop. The vessel walls become hard and less elastic; fibrous tissue forms and calcification takes place. This is a serious situation, as has been pointed out previously. When this occurs, it opens the way for clot (thrombus) formation, and the complications arising from this. The most dangerous complication is the risk of cardiac infarct (heart attack) occurring in the heart area, or cerebral thrombus or hemorrhage in the brain. Either of these may develop suddenly, and endanger life, or at least, the general wellbeing of the patient. Brain catastrophes can bring sudden death. But they can also include severe paralyses (strokes) of all or part of the body. If they occur in a vessel leading to the eye, partial or complete blindness may follow.
The blood vessels of the kidneys are vulnerable to persistent changes in blood pressure. Renal pathology and ultimate renal disease can occur and may eventually cause death.
Often the blood vessels of the retina of the eye are involved. Examination of the retina can provide valuable information as to the severity and internal progression of hypertension.
“Silver wire” appearances, “A-V nipping” and “exudates” are common findings. The vessels tend to alter and have the appearance of fine silver wires. Where an artery crosses a vein, a narrowing or “nipping” occurs. Exudates are a more serious complication, and present a grave outlook if they are there in abundance.
The retina of the eye is the only place where blood vessels can be seen under direct vision. The doctor uses a special instrument called an ophthalmoscope.
With this device a light is focused through the lens of the eye onto the back portion of the eye, the retina. The doctor then peers through the lens system and can actually see the blood vessels coursing over the retina. This can be helpful in diagnosing blood-pressure disabilities. In some patients, the pressure develops at a rapid rate and increases to a serious degree, affecting various organs acutely.
The term malignant hypertension is given to this particular variety. There has always been considerable difference of opinion among medical practitioners as to what constitutes elevated blood pressure. The range may be considerable. However, it is now generally held that 140/90 represents the upper limits of normal. Some claim that 135/85 should be regarded as the upper levels of the normal range.
The diabetic is subject to a large number of complications, many of them uncomfortable, some crippling, some extremely serious and life-endangering – a diabetic coma, for instance, which needs immediate emergency treatment.
Infections are common, varying from local boils, to chest, bladder and lower-limb infections. The nerves and kidneys may be adversely affected, and the lenses and retina (light-sensitive part) of the eye affected. Diabetic must know the types of complications that are likely. In this way the patient can be on the lookout for them, thus taking a more intelligent interest in his or her overall general welfare.
Arterial Disease of Lower Limbs
The diabetic is much more liable to develop arterial disease, including disease of the vessels that go to the heart and brain. But the vessels that usually suffer most are those supplying blood to the lower limbs. Frequently these are severely affected with so-called atherosclerosis, which may gradually worsen until it develops into obliterative arterial disease.
This means that the blood supply may become extremely deficient. The pulse in the lower limbs becomes barely perceptible or totally disappears. The serious consequence is that infections may readily become firmly entrenched, for the supply of oxygen and food is deficient.
Even more seriously, gangrene can take place. Medication is often ineffective. Rarely will vessel grafting assist (for it is often in the lower vessels of the feet where the main problem lies). Surgical amputation is often the only form of relief, this being carried out earlier rather than later, so that the patient may become accustomed to wearing prosthesis (artificial limb).
This is a serious medical emergency, and must have immediate expert attention to avert death. Most frequently it occurs in a diabetic who has some concurrent infection and has stopped taking insulin, probably because of a smaller food intake. This may be life endangering. Sometimes the patient may lapse into a coma as the first indication of this disorder, but this is unusual. In some cases the diabetic is foolish, failing to carry out the treatment properly. Such patients are a menace to themselves and their medical adviser and are asking for trouble.
Often a coma will come on as metabolism becomes increasingly disturbed, so called ketosis. This may rapidly slip into coma. It may occur slowly, the patient lapsing into unconsciousness. The skin and tongue are dry; pulse is reduced in force, blood pressure below normal, breath smelling of acetone, urine having marked amounts of sugar and ketone bodies in it. The blood sugar is usually over 400 mg per cent. In principle, it is the very opposite to the hypoglycemic bouts that too much insulin produces.
Diabetic coma is a major emergency that requires immediate hospitalization and expert handling. The doctor, aware of the diagnosis, may inject 100 units of soluble insulin before sending the patient to the emergency ward. Here, the patient will be under expert supervision until a satisfactory response is evident.