### Theory:

We looked at the effects of drugs, tobacco, alcohol, and poor lifestyle choices on our health in the previous topics. If we consider the root cause of heart diseases, it all leads to be one of the factors mentioned in the above list.

The heart is a blood-pumping organ. The primary function of the heart is to circulate blood throughout the body. It carries oxygen and nutrients to the tissues while removing carbon dioxide and wastes from the blood. It also helps to maintain normal blood pressure throughout the body. It also transportsoxygen from the lungs and removes carbon dioxide.

The human heart

So, if our heart is afflicted by a disease, our entire body's functioning will fail. Hence it is essential to maintain an excellent lifestyle to protect our hearts. This section will look at heart disease, its causesrisk factors and symptoms.

Cardiovascular disease (CVD) is characterised by heart and blood vessel problems. The most common type is coronary heart disease (CHD), caused by cholesterol accumulation in the blood vessels.

It generally develops slowly over a long period, beginning in childhood, ranging from a fatty streak to a fibrous complicated plaque. It causes blood vessel narrowing, which leads to atherosclerosis in the large and medium-sized arteries that supply oxygen to the heart muscle. It causes sudden ischemia (insufficient blood supply to the heart muscle) and myocardial infarction (death of the heart muscle tissue).

Important!
Atherosclerosis is when patchy deposits of fatty material form in the walls of medium and large-sized arteries, resulting in reduced or blocked blood flow. It is caused by repeated damage to the artery walls.
Atherosclerosis

Risk factors:
1. Hypercholesterolemia - high blood cholesterol
2. Hypertension - high blood pressure
The diseases mentioned above are the leading causes and contributing factors to heart disease. If untreated, it could even cause severe damage to the brain and kidneys, eventually leading to stroke.

Causes:

A few medical conditions and lifestyle choices that can cause or increase the risk of heart disease which include:
• Heredity
• Diet rich in saturated fat and cholesterol
• Obesity
• Increasing age
• Cigarette smoking
• Emotional stress
• Sedentary lifestyle
• Excessive alcohol consumption
• Physical inactivity
A picture explains the causes and symptoms of heart disease.

Symptoms of heart disease:

• Shortness of breath
1. For Indians, a desirable blood cholesterol level should be less than $$200$$mg/dl. As blood cholesterol levels rise from $$200$$ to $$300$$mg/dl, the risk of coronary heart disease rises gradually.
2. $$HDL$$ (High-Density Lipoprotein) or "good" cholesterol lower the risk of heart disease, whereas $$LDL$$ (Low-Density Lipoprotein) or "bad" cholesterol increases the risk.