Could it be something bad if i have urticaria?

Urticaria - hives: Most urticaria represent mild symptoms of allergy with a raised red bump on the skin and itching. They usually come on abruptly with a lot of itching. Most urticaria represent just a local skin reaction to some antigen. Local reactions are usually not very severe. The problem is that over time local reactions can progress to systemic reactions with repeated exposure, and that could cause high risk.

Comlex answer: Urticaria is potentially a very challenging disease. Depending upon the duration of hives, timing of reaction, causes urticaria could be relatively innocuous or the harbinger of more serious disease. Urticaria should be taken very seriously and a thorough evaluation is indicated.