Medical school is harder. It takes over your entire life. At my medical school the first two years covered basic sciences. We covered the same material on genetics in one week that I had learned in a one semester class as an undergraduate. We spent days in classes and evenings studying.
The last two years were spent on clinical rotations. We would see patients all day and study at night. Sometimes we had to take call and stay in the hospital overnight to cover patient care.
Once you graduate, you need another three to eight years as an intern/resident to complete your training. It is very hard to be employable without a speciality. Although there are regulations limiting the number of hours of work, many programs have ways to get around the rules. Sixty to eighty hour weeks are common.
When you complete your training and start work, you find your income is determined by what insurance companies are willing to pay. Lawyers charge by the hour and set their own income.