Does acupressure really work for common diseases?

Depends. Depends on what you mean by common diseases. If you are referring to asthma, allergies... Yes, it can help. We believe that acupuressure and acupuncture change the behavior of the immune and hormonal systems, hence how they can help. Now, food reactions and a whole host of other problems can also lead to the same symtpoms, in which case acupressure may be less effective.
For many. Acupressure can be used to treat many conditions including nausea, abdominal & back pain, headache, fatigue, anxiety, asthma, bronchitis, stress, menstrual cramps/ pms, joint pain, decreased libido, anxiety, depression, indigestion, acne, tmj, carpal tunnel, sinus pressure, gerd, immune system deficiencies and more.