My friend and I consumed the same amount of alcohol yesterday. After a few hours of sobering up we tested ourselves with a breathalyzer. Taking into account he is 72kgs and I am 102kgs what would cause his reading to be .19 and mine to be 0.0. We have used this device many times previously and are familiar with the correct operation of it. After many trials the results did not change. I wonder if he his liver is not processing the alcohol very well. We are both 53 years of age and he has been a regular heavy drinker for years where I may drink a beer once or twice a week. He does not show any other signs of liver damage ie skin, abdomen pain, stool issues, yellowing of eyes etc. So my question is does his liver stand out as a more likely concern if the breathalyzer readings are correct or can we put it down to other factors such as weight difference? Hope this makes sense...thankyou...regards Peter