Smoking raises the chance of heart problems and stroke. It harms the blood vessels and heart. Chemicals in tobacco smoke cause swelling in the blood vessels. This leads to plaque forming inside them. Less blood gets through the narrowed vessels.
Heart attacks and strokes become more likely. Smokers are also more prone to a condition where blood flow to the arms or legs weakens (due to
peripheral artery disease), which can lead to amputation in severe cases.
Smoking cuts oxygen to the heart. In this situation, blood becomes thicker, raising the possibility of clots forming. Smokers using oxygen therapy for lung problems still face severe damage to the heart and vessels. However, quitting smoking right away lowers these risks. That allows the body to start fixing the damaged blood vessels slowly.