What is the difference in symptoms between asthma and emphysema?

Very similar...: ...Symptoms, except that an asthma attack is reversible, emphysema is not.

Different causes: Ephysema is almost always caused by smoking except for a rare form of hereditary emphysema. If you never smoked then i can be almost 100% certain you don't have emphysema. A chest x-ray of an asthmatic can look "over inflated" (asthmatics have more trouble blowing air out than inhaling it) and sometimes is incorrectly interpreted as "emphysema" especially in a non-smoker.

Same symptoms...: Different day. Asthma occurs at any age, emphysema is rare under age 40. Symptoms - coughing, wheezing, shortness of breath are the same. Bronchodilators & controller medications like inhaled corticosteroids are very effective in asthma; classically not effective in emphysema. Not so fast, many patients with emphysema have an asthmatic component & get significant relief with these drugs.

Similarities: Both are obstructive lung diseases. Asthma can be seen in children and adults. It is spasm of airways, and can be acute and chronic. Emphysema is usually in older people, and can be acute on chronic also. It's hallmark is destruction of the air sacs of lung as well as small airways. Long-term, uncontrolled asthma clinically looks similar.