Alopecia Areata is not contagious but tinea or ringworm of the scalp is contagious
Alopecia Areata usually causes very distinct circles of hair loss on the scalp but can affect the eyebrows, lashes or beard. It is an autoimmune-like condition where the body is attacking one's own hair. This is not contagious. Ringworm or tinea capitis can also cause circular areas of hairloss on the scalp but it is more often seen in children and it's very unlikely to affect the eyebrows. There is also usually redness or flakiness associated with this condition due to fungus. You should probably seek out care from you primariy doctor or a dermatologist to properly diagnose your hair loss.
Eyebrow Thinning and Hair Loss
Alopecia areata is not contagious and therefore you cannot catch it from someone who has that diagnosis. See your family doctor for a history and examination and rule out general medical conditions that can result in hair loss such as hypothyroidism. After proper investigations a correct diagnosis may become evident.
Alopecia areata is not contagious. But if you are suffering from frontal hair loss and hairloss in the eyebrows it might be wise to do a biopsy and rule out other conditions.
Very few hair loss conditions are contagious. Alopecia areata is not contagious. If you are worried about your hair, please see a specialist.