When bottom number of blood pressure is 100?

Normal Blood Pressure

Blood pressure is measured by taking two different measurements of the pressure within your arteries: systolic pressure and diastolic pressure. Systolic pressure, the first or top number of the blood pressure reading, is the highest level of pressure in your arteries, which occurs when your heart muscle contracts and forces a burst of blood into the aorta. Diastolic pressure, which is the bottom number, is the pressure that exists within your arteries between heart muscle contractions, which is when your heart is filling with blood.

If your blood pressure reading is less than 120/80 millimeters of mercury or mm Hg (the unit of measurement that is used to describe blood pressure), you have normal blood pressure. This means that your systolic pressure is less than 120 mm/Hg and your diastolic reading is less than 80 mm/Hg.

Blood pressure fluctuates throughout the day, so it is normal for your blood pressure to change from reading to reading. Your blood pressure is considered normal if it is less than 120/80 mm Hg most of the time.

Prehypertension: When Blood Pressure Is Above Normal

If your blood pressure is higher than 120/80 mm Hg — meaning that one or both of these numbers are higher — your doctor may take a number of readings over time, and possibly have you track your blood pressure at home to get more information before making a diagnosis of hypertension.

If you have prehypertension, your blood pressure is above normal, but not high enough to warrant a diagnosis of hypertension. Prehypertension is considered to be a systolic pressure of 120 to 139 mm Hg or a diastolic pressure of 80 to 89. If your systolic pressure and diastolic pressure are not in the same category, you are considered to be in the more severe category of the two.

People who have prehypertension are likely to eventually develop hypertension, unless they take steps to lower their blood pressure. If you have prehypertension, your doctor may recommend healthy lifestyle changes to prevent or delay the onset of hypertension.

Stage 1 and Stage 2 Hypertension

Hypertension is diagnosed when your systolic pressure is 140 mm Hg or above or when your diastolic pressure is 90 or above. In people who have diabetes or kidney disease, hypertension is diagnosed when blood pressure is 130/80 mm Hg or higher. The higher your blood pressure is, the greater your risk of developing blood pressure-related complications such as heart disease, heart failure, stroke, or kidney failure.

The first stage of hypertension is called stage 1 hypertension. The systolic pressure is 140 to 159 mm Hg or your diastolic pressure is 90 to 99 mm Hg. The next stage of hypertension, stage 2 hypertension, is diagnosed when your systolic pressure is 160 mm Hg or higher or your diastolic pressure is 100 mm Hg or higher.

A diagnosis of hypertension means that you need treatment to get your blood pressure under control. Your doctor may recommend lifestyle changes and high blood pressure medication to help manage your blood pressure.

Hypertensive Crisis: A High Blood Pressure Emergency

• Focus on heart-healthy foods.
• Limit saturated and trans fats.
• Reduce sodium in your diet.
• Eat more potassium.
• Lay off the caffeine.
• Cut back on alcohol.
• Ditch sugar.
• Switch to dark chocolate.

When the bottom number of blood pressure (diastole) is over 100 mmHg, it may be called diastolic hypertension (DHT). The normal range of diastolic pressure should be 60 to 80 mmHg in adults. Anything above this is considered abnormal (hypertension).

Each time that you have your blood pressure measured, it is important that the test is carried out under similar conditions to ensure that the results are consistent. If you have a low blood pressure reading, your GP will first consider the everyday causes that might have affected it, before considering the possible underlying causes.

Many factors have a daily, or sometimes even hourly, effect on your heart and circulation. Below are things that could affect your blood pressure and, in some cases, may cause low blood pressure.

If your blood pressure is still considered low after taking into account everyday factors such as those listed above, there may be another cause. Some possibilities are explained below.

Some medication may cause hypotension as a side effect. This tends to be orthostatic, or postural hypotension (low blood pressure when you stand up or change position). Examples of medication that can cause hypotension include:

Your GP will discuss any possible side effects with you when prescribing medication. While you are taking medication, your blood pressure will be carefully monitored if you are considered to be at risk of hypotension.

If you have an acute (short-term) illness, your blood pressure will be measured regularly because it is a good indicator of the severity of your illness. A heart condition, such as heart failure or a heart attack, can also cause low blood pressure, as your heart may not be able to pump blood around your body.

Autonomic disorders affect your autonomic nervous system and they can cause hypotension. Your autonomic nervous system is part of your nervous system (the network of cells that carry information around your body). It controls the bodily functions that you do not actively think about, such as sweating, digestion and the beating of your heart.

The autonomic nervous system also controls the widening and narrowing of your blood vessels. If there is a problem with it, your blood vessels could remain too wide, causing low blood pressure. In particular, autonomic disorders tend to cause orthostatic hypotension.

Some examples of autonomic disorders are:

The adrenal glands are two small glands that are located just above your kidneys. They produce hormones that control your blood pressure and maintain the balance of salt and water in your body. One of the hormones they produce is called aldosterone, which is responsible for controlling the amount of salt in your body.

If your adrenal glands become damaged - for example through an infection or a tumour - the production of aldosterone may be reduced, resulting in a loss of salt from your body. This can cause dehydration which, in turn, leads to low blood pressure.

If a problem with your adrenal glands is diagnosed, it can be treated by increasing the amount of aldosterone in your body. This could also be a symptom of Addison’s disease (a condition in which the adrenal glands cannot produce enough of the hormones cortisol and aldosterone). Addison’s disease can also be treated with medication.

Low blood pressure can also be caused by serious injuries or burns, particularly if you have lost a lot of blood. This can mean that there is less blood being pumped around your body. Low blood pressure can also occur if you go into shock after having a serious injury.

Other kinds of shock are described below.

Septic shock and toxic shock syndrome are caused by bacterial infections. The bacteria attack the walls of the small blood vessels, causing them to leak fluid from the blood into the surrounding tissues. This causes a significant drop in blood pressure (severe hypotension).

Anaphylactic shock, or anaphylaxis, is caused by an allergic reaction to something - for example, a wasp sting or a peanut. During an allergic reaction, your body produces a large amount of a chemical called histamine, which causes your blood vessels to widen and leads to a sudden, severe drop in blood pressure.

Cardiogenic shock occurs when your heart cannot supply enough blood to your body, so your blood pressure drops. This can happen during a heart attack.

If an individual has hypertension, they have an increase in both systolic and diastolic blood pressure.

However, elevated diastolic blood pressure occurs in isolated diastolic hypertension (IDH). Doctors classify stage 1 IDH as a diastolic blood pressure of 80–89 mm Hg diastolic blood pressure. They classify stage 2 IDH as diastolic blood pressure above 90 mm Hg.

Learn more about blood pressure readings here.

IDH is uncommon and accounts for less than 20% of hypertension cases.

Doctors do not understand why an individual may develop diastolic hypertension. They suggest the narrowing of arterioles causes it due to hormones in the body.

Common causes of isolated diastolic hypertension are:

A study demonstrated the link between severe sleep apnea and higher diastolic blood pressure.

However, some potential and preventable causes of IDH also include the following:

Doctors usually associate hypertension with obesity. However, they also link being overweight and having obesity to IDH.

To reduce the risk of IDH, a person can take steps to reach a moderate weight through diet and exercise.

If they find it challenging to make dietary changes or increase physical activity, a doctor can suggest alternative weight management options.

Some studies show that alcohol consumption contributes to IDH.

To help prevent high blood pressure, the AHA recommends that males do not consume more than two alcoholic drinks per day and females no more than one alcoholic drink per day.

The AHA states that one drink is either:

Learn more about ways to reduce alcohol consumption here.

Research associates smoking with IDH. For example, a study in China found that among individuals age 90 and over, current or previous heavy smoking increased diastolic blood pressure.

Learn more about ways to give up smoking here.