It's incredibly usual for people to get nosebleed on their very first open water dive only because they don't equalize properly. Some scuba divers get nosebleeds after diving, immediately or with some delay that can be as extended as a day or so. But most frightening nose bleeding is a nosebleed underwater. Since underwater nosebleed normally happens for the first time whilst you descend, we'll focus here on this aspect only. Nose bleed happens to many scuba divers, not just beginners. Not knowing how properly equalize air pressure while descending is only one of numerous reasons causing scuba divers nose bleed while underwater. If nose bleeding happens, it is important to identify the nature of this problem in your specific case in order to take preventive measures so your further scuba diving experience would be enjoyable and, specifically, nosebleed free. It would be pity if nose bleeding caused you give up the wonderful hobby, which scuba diving is. Some causes of nosebleeds are very simple and can be removed with just a little of knowledge and exercising. Say, scuba diver nose bleeding at smaller depths at the stage of the descent may be side effect due to mask squeeze resulting from failing to equalize the pressure in the mask against the growing water pressure. Lower pressure in the mask, which is most commonly directly responsible for starting nose bleeding, can be easily avoided with just a little training. In many cases descending at a slower rate along with frequent equalization will resolve the issue. Bleeding can also be caused by injury from squeezing your nose too vigorously in the repeated attempts to clear your Eustachian tubes. Many times said, but not always followed, there's a rule to never dive with the congested nose interfering with your efforts to blow your sinuses. Ideally, you must refrain from scuba diving even with slightly blocked sinuses, but in reality many scuba divers just resort to nasal steroids as decongestant. Nose bleeding can also be an indicator of a much serious and adverse health condition you may be unaware of. In any case, consult your doctor, especially if your after dive, and, especially, underwater nosebleed is regular, excessively persistent, or painful. A diver who experiences frequent nosebleed should by no means be frivolous about it. The point is that with every nose bleeding your nasal mucosa hosting bacteria gets connected with your bloodstream, which can result in serious sinus infection.