Will an occasional cigarette damage your health?
Studies can now measure the immediate changes in our bodies as we smoke a single cigarette, from a rise in blood pressure to a change in the gases in our blood stream.
Here's what happens when we smoke a cigarette:
Although we may feel more relaxed as we smoke, our blood pressure and heart rate both increase, the heart pumps differently, and the blood flow to the capillaries decreases.
Blood carbon monoxide levels increase. "Carbon monoxide takes the place of oxygen in some of your red blood cells, and it sticks on to the red cells for days, preventing oxygen from being carried by these cells", warns Currow.
Other changes happen in our airways: the little finger-like cilia which keep airways clear of phlegm are 'stunned' by chemicals in the smoke and tiny muscles in our airways contract, constricting them.
There are also measurable changes in the immune system.
These and other changes have a cumulative effect and over time they can eventually lead to cancer (including cancer of the lung, pancreas, oesophagus, and bladder) as well as non-cancerous, but potentially lethal, conditions such as heart and vascular disease and lung diseases like emphysema.