What is the difference between cystic acne and common minor acne? D.O. Thinks my acne is maybe from hormone imbalance and gave me keflex.

Same condition. Cystic acne is just more advanced/aggressive. Treatment needs more than topicals, like adding oral antibiotics or even accutane. Keflex is not a standard rx, but it might help some. Acne is (male) hormone related, but it also aggravated by stress, etc.
"Just Deeper" Hello, It's all just "plain old acne" except the cysts are deeper and scarier. Same process, same cause, overlapping treatments. For example, Keflex is used for all types of" plain old acne". This video may help get your mind around ths situation: https://www.youtube.com/watch?v=xyDI1EHkb04 I'll be here if you have any questions. Have a great day, -Dr. Neal Schwartz.
Hormonal acne. If you are not on any oral contraceptives, need to be tested for hormone levels. Women may have hormone imbalance due to polycystic ovary syndrome which may also have irregular menses, hair loss or excess hair growth. There are meds to help. Cystic acne is one form if acne with larger red acne lesions. Usually also has blackheads & whiteheads as well. Antibiotics not great for hormonal acne.