Re: slight heaviness in breathing.
Might I urge you not to start a bad habit that will harm your health, not to mention the cost to maintain such a habit. I believe the average smoker spends almost $2000 a year and many would love to quit, but find it too difficult. Why start?
I would imagine 4-5 cigs is quite a hit for a non-smoker. I think your lungs are trying to tell you something. Its like a first time drinker getting a hang-over. Sometimes our bodies have better sense than we do. However, if your sysmtoms persist ...see your doctor.