Yes, smoking can cause gangrene through various mechanisms. The human body constantly depends on oxygen and nutrients, which are distributed throughout the organism by the blood, with nutrients absorbed through digestion and oxygen through the lungs.
Gangrene occurs when tissues stop receiving blood supply and begin to rot. It generally affects the most distal parts of the body, such as fingers of the hands and feet, where blood arrival is more difficult, but it can spread if not treated.
The consequences of this condition are serious; when tissues suffer necrosis, they become highly vulnerable to bacterial infections. These infections can enter the bloodstream, causing septic shock, which often requires the amputation of affected limbs to contain the progression of the infection.
The act of smoking worsens this situation because tobacco smoke introduces harmful substances into the blood, such as tar, carbon monoxide, and nicotine, which damage blood vessels in multiple ways.
One effect is the narrowing of blood vessels: chemicals irritate the cells of the arterial walls and decrease the production of nitric oxide, a vital molecule for dilation. Additionally, the inflammatory response of cells against these harmful substances makes the flow of oxygen- and nutrient-rich arterial blood even more restricted.
Smoking also promotes atherosclerosis, a chronic vascular disease characterized by the accumulation of fat, calcium, and cholesterol plaques in the arteries, which limits blood flow.
Another critical factor is the carbon monoxide released by tobacco, which reduces the blood's capacity to carry oxygen. Red blood cells, which contain hemoglobin to capture oxygen in the lungs, bind to carbon monoxide with higher affinity, forming carboxyhemoglobin (COHb). This binding drastically reduces the oxygen transport capacity, hindering its absorption by tissues, which leads to cell death due to lack of oxygen.
Besides gangrene, smoking is linked to various cardiovascular problems. World Health Organization (WHO) data indicates that smoking is the main cause of 10% of all cardiovascular diseases globally, and risks increase with exposure. Previous studies have shown that former smokers with peripheral artery disease (PAD), a condition that can lead to gangrene, had a lower risk of death or amputation compared to those who continued smoking.
