Let’s start with a disclosure: yes, today we’re talking about smoking damages and its effect on our sleep and overall health. According to the CDC (Centers for Disease Control and Prevention), smoking leads to illness and diseases among more that 16 million people in the US. Tobacco and nicotine consumption are known to be a significant cause of cancer, cardiovascular disease (heart conditions, atherosclerosis, stroke, etc.), diabetes, lung disease and many more health (or actually illness) conditions. Furthermore, smoking has been shown to be a contributing risk factor to problems of the immune system, tuberculosis and eye diseases. Having said that, this is still just the tip of the iceberg - smoking is a major risk factor for more than 90% of unhealthy conditions, worsening the chances of comorbidity, and the rest are still in research. 

On your journey towards better health through better sleep, you should take under consideration that both smoking and sleeping affect the same processes of cell cycles, tissue renewal and organ function, just in the opposite direction. While good sleep enhances those processes into a better state of all levels - from the single cell to entire organ levels, smoking damages these processes and causes unwanted outcomes.

The idea guiding us while creating our sleep hygiene routine is to reduce interruptions and try to isolate different sleeping variables from the common ongoing damage our body gets physiologically. We try to finish eating enough time ahead of bedtime in order to provide our digestive system with the rest it needs, same goes for blue light and melatonin production, as well as meditating to make the process of falling asleep easier. 

To enhance your experience, enjoy positive outcomes and get good feedback from your mind & body, it would be best to reduce the effect of negative possible outcomes such as the ones resulting from smoking. 

It appears that although the existing habit of smoking has its benefits of stress reduction, anxiety relief, and even the social part existing in some scenarios, reducing (and surely also quitting) smoking has a lot to offer, too. 

Prioritizing our long term health conditions is a complicated mission, yet opposed to other suggestions that are not yet shown to be effective, this choice has evidence based incentive, making it a little easier one. 

https://www.cdc.gov/tobacco/data_statistics/
https://www.cdc.gov/tobacco/basic_information/
https://www.who.int/tobacco