Interesting question, but honestly difficult to answer.

Both the fields you have mentioned are two extremes and both have an importance in their own respects and fields.

If you are analytical and like to experiment and learn, always in search for answers and like to solve issues at hand, then both the fields are equally good for you.
Another important aspect is, either your love and to deal with either Machines, it can be anything right from automobiles, to home appliances to computers to mobiles. Dislocating the objects to study them and then making an effort to join them, then you are more of an engineering material.

But on the other hand if you like to deal with people, happy to know and learn and discover how the bodily functions are and how can certain things externally affect the human body or mind, then medical is the line for you.

This is a simple analysis, but will definitely not give you the complete picture about choosing a career best suited for you.

Best will be a self analysis, like knowing your potentials and based on your strengths choosing a career.
Since apart from just being analytical, both of them require another skills and potentials like knowing how good is your visualization skills, observation skills, body activity level, emotional level and at the same time liking towards the subject.

In case you can do a self analysis regarding what are your strengths and your weakness and where exactly do you see yourself working in the future. You can take help of your parent or elder siblings, but not friends.
In case you are unable to do it by yourself, best would be to get yourself an Aptitude testing. It will give you an accurate information about your potentials and will help you to make a conducive decision.

Wish you good luck..............