How does cigarette smoking can lead to hypertension? -

Inhalation of tobacco smoke causes several immediate responses within the heart and blood vessels. Within one minute the heart rate begins to rise, increasing by as much as 30 percent during the first 10 minutes of smoking. Carbon monoxide in tobacco smoke exerts its negative effects by reducing the blood’s ability to carry oxygen. Smoking tends to increase blood cholesterol levels. Furthermore, the ratio of high-density lipoprotein (the “good” cholesterol) to low-density lipoprotein (the “bad” cholesterol) tends to be lower in smokers compared to non-smokers. Smoking also raises the levels of fibrinogen and increases platelet production (both involved in blood clotting) which makes the blood viscous. Carbon monoxide binds to haemoglobin (the oxygen-carrying component in red blood cells), resulting in a much stabler complex than haemoglobin bound with oxygen or carbon dioxide--the result is permanent loss of blood cell functionality. Blood cells are naturally recycled after a certain period of time, allowing for the creation of new, functional erythrocytes. However, if carbon monoxide exposure reaches a certain point before they can be recycled, hypoxia (and later death) occurs. All these factors make smokers more at risk of developing various forms of arteriosclerosis. As the arteriosclerosis progresses, blood flows less easily through rigid and narrowed blood vessels, making the blood more likely to form a thrombosis (clot). Sudden blockage of a blood vessel may lead to an infarction (e.g. stroke). However, it is also worth noting that the effects of smoking on the heart may be more subtle. These conditions may develop gradually given the smoking-healing cycle (the human body heals itself between periods of smoking), and therefore a smoker may develop less significant disorders such as worsening or maintenance of unpleasant dermatological conditions, e.g. eczema, due to reduced blood supply. Smoking also increases blood pressure and weakens blood vessels.

It constricts the blood vessels, making the heart have to beat harder to push the blood though the smaller vessels. Its with any Tobacco product, not just cigs. So smokeless tobacco is just as bad (if not worse... ).

Nicotine, and most probably other chemicals and free radicals, in cigarette smoke irritate the endotheliium, the lining of your arteries. This will cause an inflammation response. This is an actual cause of atherosclerosis. As this process continues a buildup of lipids and cholesterol will deposit at the injury site. This plaque can then restrict blood flow through the arteries, thus causing a rise in blood pressure. Cigarette smoking is a true cause of atherosclerosis, as it actually initiates the process

cigarettes have substance that fastens the process of atherosclerosis( calcification of blood vessels) , where they become more rigid and more resistant to blood flow, which increases the blood pressure, it also may incarease blood hemoglobin and blood volume, in response to decrease oxygen intake...

simply, it constricts the blood vessels.