第一章 Hypertension

What is hypertension

Hypertension is a condition in which the blood vessels have persistently raised pressure

Blood pressure is measured using a system of units called millimeters of mercury (mmHg)
Written as two number
- Systolic pressure
  - Pressure in the blood vessels when the heart contracts or beats
- Diastolic pressure
  - Pressure in the vessels when the heart rests between beats
Normal if readings is less than 120/80
Diagnosed if readings on both day is higher than 140/90

Cardiac output
- The measurement of blood flow from the heart through the ventricles
Compliance
- The ability of any compartment to expand to accommodate increased content
Blood volume
- The total amount of blood
Resistance
- Blood viscosity
  - The thickness of fluid that effects their ability to flow
- Vessel length
  - Directly proportional to its resistence
- Vessel diameter
  - The effect of vessel diameter on resistence is inverse

Age
Ethnicity
Genetics
Gender
Other risks factors
- Obesity
- Chronic obstructive pulmonary disease
- Diabetes
- Gestational hypertension

Excess dietary salt
Poor diet and obesity
Excess alcohol comsumption
Lack of physcial activity
Deprivation adn socio-economic status
Mental health and stress
Examples
- Nicotine - vasoconstrictor $\rightarrow$ vessel diameter decreases
- Inactivity and fatty food $\rightarrow$ blood viscosity increases
- Consume more salt $\rightarrow$ retain more water in blood $\rightarrow$ blood volume increases

Plaques: hinder the flow of blood
- Damage the cells of the arteries’ inner lining $\rightarrow$ create small tears and form scar tissue $\rightarrow$ catch substances like fat and cholesterol.
Anerysm: can form in any artery, but most common in the largest artery(aorta)
- Hypertension weakens arteries $\rightarrow$ vessel wall enlarges and forms a bulge $\rightarrow$ can rupure and cause life-threatening internal bleeding

Enlarge left heart
- Hypertension forces your heart to work harder $\rightarrow$ causes the left ventricle to thicken $\rightarrow$ increases risk of eart attack, heart failure, and sudden cardiac death
Coronary artery disease
- Narrow and damaged arteries $\rightarrow$ have trouble supplying blood to your heart $\rightarrow$ causing chest pain (angina), irregular heart rhythms (arrhythmia), or a heart attack
Heart failure
- Heart muscle weakens and works less efficiently $\rightarrow$ overwhelmed heart begins to fail

Transient ischemic attack(TIA)
- Hypertension $\rightarrow$ hardening of arteries and blood clots $\rightarrow$ the flow of blood supply to the brain is disrupted temporarily
Ischemic stroke
- Hypertension can cause blood clots to form $\rightarrow$ block blood flow in the brain, causing ischemic stroke
Hemorrhagic stroke
- blood vessels damaged by hypertension in the brain rupture, causing hemorrhagic stroke
Vascular dementia
- As hypertension caused narrowed or blocked arteries, and blood flow to the brain is limited

Kidney scarring(glomerulosclerosis)
- Hypertension $\rightarrow$ tiny blood vessels within the kidney(glomerrulus) become scarred $\rightarrow$ kidney is unable to effectively filter fluid and wastee from your blood
Kidney failure
- Accumulation of dangerous levels of fluid and waste

Retinopathy
- Retina: light-sensitive tissue at the back of your eye $\rightarrow$ $\to$ damage to the retina $\rightarrow$ $\to$
  - bleeding,
  - blurred vision
  - complete loss of vision
Choroidopathy
- Fluid build-up under the retina
  - Result in distorted vision and scarring
Optic neuropathy
- Blocked blood flow can damage the optic nerve
  - bleeding and loss of vision

Diuretic
- Shed excess sodium and water $\rightarrow$ decrease blood volume
- Side Effects
  - Deplete the body’s potassium $\rightarrow$ muscle weakness, leg cramps, and fatigue
Beta-blocker
- Slow the heart rate $\rightarrow$ heart doesn’t have to work as hard
- Side Effects
  - Insomina, dizziness, fatigue, cold hands and feet, and erectile dysfunction
ACE inhibitors $\rightarrow$ $\to$ Angiotensin-converting Enzyme
- Reduce the body’s supply of angiotensin II (a substance that makes blood vessels contract and narrow) $\rightarrow$ more relaxed, dilated arteries
- Side Effects
  - Dry cough, skin rash, or dizziness, and high levels of potassium
- Women should not become pregnant while taking an ACE inhibitor
ARBs $\rightarrow$ $\to$ Angiotensin Receptor Blockers
- Block receptors for angiotensiin II $\rightarrow$ prevent the chemical’s artery-tightening effects
- Side Effects
  - Dizziness, muscle cramps, insomnia, and high levels of potassium
- Women should not become pregnant while this medication
Calcium channel blockers
- Calcium causes stronger heart contractions $\rightarrow$ calcium channel blockers slow the movement of calcium into the heart and blood vessels
- Side Effects
  - Dizziness, heart palpitations, swelling of ankles, and constipation
- Take them with food and milk, and avoid grapefruit juice and alcohol

Meditation
- Put the body into a state of deep rest, which can lower blood pressure
Yoga
Tai chi
Should be combined with other lifestyle changes