IRS: "You can include in medical expenses amounts paid for transportation primarily for, and essential to, medical care."

"You can include in medical expenses amounts you pay for transportation to another city if the trip is primarily for, and essential to, receiving medical services. You may be able to include up to $50 per night for lodging."

"You cannot include in medical expenses a trip or vacation taken merely for a change in environment, improvement of morale, or general improvement of health, even if the trip is made on the advice of a doctor."

And remember that medical expenses are only tax deductible to the extent they exceed 7.5% of your adjusted gross income.