Is it possible for dandruff/dry scalp to cause balding/thinning hair for a 21 year old? (photo)

Dandruff is a scalp condition and it does not cause genetic hair loss. If you are concerned it is best to see a doctor.

Hey Brain,
I think the fact that you have two conditions i.e. dry scalp / dandruff and now hair loss / baldness might have caused you to assume that they are either related in someway or one is causing the other.
This most certainly may not be the case. Hair loss happens due to variety of other factors. See picking dandruff and dry scalp can cause hair fall to some extent but not to the point of baldness.
Of course these are all just welleducated guesseswe are making because of limitations of information in your question.
You should take time off and consult with a good trichologist in your city. A one on one consultation will help the doctor analyse the specific conditions that maybe causing baldness in your case and suggest solutions.
Hope that helps.

You may have the beginning of male pattern balding if you are noticing thinning hair. It would behoove you to see a hair restoration specialist sooner rather than later to start you on finasteride.  Finasteride will help slow down the hair loss if it is male pattern balding as well as possibly regrow new hair.  Dandruff is not a cause of hair loss, however seborrheic dermatitis which is common cause of dandruff can accelerate hair loss in someone who is genetically prone to patterned baldness.

These are not typically causes of hair loss. It's a good idea to see a specialist as rarely certain issues that cause flaking can lead to hair loss. But dandruff is not one of them.The most likely causes, by far, in a 21 year old male, is male pattern balding.

Hairloss is purely genetic. DHT is the cause of hairloss. Dandruff and dry scalp has not been shown to cause hairloss.