I have kept a health log in Excel for almost 5 years and yes, it is helpful. Countless tests, appointments, conditions, symptoms...all noted there and easily accessible. I use it less today but still record appointments and tests and any change in symptoms.
The advantage of using excel is that I can sort the data any way I want in seconds if necessary. If you are interested I have a sample file and could email it to you. Only a few columns but it works like a charm.
MCTD (lupus, scleroderma, polymyositis). Diagnosed 2005. Kidney, liver, GI tract, dysphagia, raynauds, Barretts esophagus, quadriplegic in 2005. Recovered and now active in skiing, tai, chi, hiking, golf. Meds: prednisone 2.5mg, imuran 25mg, amlodipine, benazapril, omeprazole, potassium, folic acid, vitamins, maxide and various supplements and vitamins.
Remain optimistic and you can overcome the odds.