Why humans get chronic diseases II:
Smoking and alcoholism are important risk factors for various chronic diseases, such as malignant tumors, hypertension, coronary heart disease, stroke, and chronic obstructive pulmonary disease. It is known that smoking can cause or exacerbate various malignancies, such as lung cancer, bladder cancer, oral cancer, pancreatic cancer, gastric cancer, and esophageal cancer. The impact of smoking on lung cancer and chronic obstructive pulmonary disease is much higher than other factors, and is closely related to the mortality rate. Smokers have a 7-14 times higher mortality rate from lung cancer than non-smokers.
The longer the smoking history and the greater the amount of smoking, the higher the risk of developing lung cancer. Smoking is associated with a 2-8 times higher risk of developing chronic obstructive pulmonary disease than non-smokers, and heavy smokers can have a risk up to 30 times higher. Tobacco damage to the human body is mainly caused by nicotine and carbon monoxide, which are produced when tobacco is burned. These dangerous factors can directly affect the heart, coronary artery, and blood. Nicotine can increase blood pressure, heart rate, and myocardial oxygen demand; carbon monoxide can block oxygen transport and utilization.
The incidence of coronary heart disease in smokers is twice that of non-smokers, and the risk of developing ischemic stroke is 1 times higher. Smoking is also closely related to acute myocardial infarction and sudden death.
Drinking alcohol for a long time is related to various malignant tumors, such as fatty liver disease, liver cirrhosis, liver cancer, oral cancer, and throat cancer. Alcohol can increase the number of platelets in the blood and lead to poor cerebral blood flow regulation, resulting in hypertension, arrhythmia, and hyperlipidemia, increasing the risk of hemorrhagic stroke. Drinking alcohol is associated with a 40% increased risk of developing hypertension in men.
Social and psychological factors, emotions, and other factors can also be important risk factors for chronic diseases. These factors can be direct causes of cancer or indirect triggers. For example, mental stress, poor interpersonal relationships, loss of loved ones, and setbacks can lead to negative emotions, which can cause depression, cancer, and cardiovascular diseases. Sudden emotional changes can also trigger acute myocardial infarction and stroke.
Biological genetic factors play an important role in the occurrence of chronic diseases, and are important risk factors for many chronic diseases, such as malignant tumors, cardiovascular diseases, and diabetes. Children of parents with high blood pressure have a 10-20 times higher risk of developing hypertension than healthy parents. The degree of inheritance of chronic diseases is called the heritability (%), and the heritability of hypertension is 60%, while that of type II diabetes is over 60%. The heritability of malignant tumors is relatively smaller.
Environmental factors, urbanization, and industrialization have greatly changed the lifestyle and living environment of the population, leading to an increase in the number of chronic diseases. The exposure of various risk factors for chronic diseases, such as smoking, alcohol consumption, sedentary lifestyle, lack of physical exercise, overweight, and obesity; family history of diseases; and mental stress, poor mental adaptation, environmental pollution, and occupational hazards, are all important causes of an increase in the number of chronic diseases.