Guides
Articles on decompression sickness, ear and sinus problems, flying after diving and medical fitness to dive. Each one links to the dive medicine sources it is based on.
These guides are general information. For a medical question, see a doctor. In an emergency, call local emergency services or your regional DAN hotline.
Safety & Dive Medicine8 min read
A 0.5 L mini scuba tank holds about 99 L of air, 2 minutes at 10 m. Lung injury risk in shallow water, recalled kits, air quality and who should use one.
Read moreSafety & Dive Medicine10 min read
How divers can prevent seasickness, which medicines to test on land before a dive day, the drowsiness risk at depth and how to vomit through a regulator.
Read moreSafety & Dive Medicine11 min read
Waiting times after decompression sickness from DAN, UHMS, DMAC and the US Navy, plus the medical review, PFO testing, flying after treatment and safer diving.
Read moreSafety & Dive Medicine12 min read
Diabetes, even type 1 on insulin, need not rule out scuba diving. UHMS/DAN, UKDMC and SPUMS criteria, pre-dive glucose checks and the hypo signal compared.
Read moreSafety & Dive Medicine11 min read
Controlled high blood pressure does not rule out diving. UKDMC, UHMS, SPUMS and EDTC limits compared, plus beta-blockers, diuretics and pulmonary oedema.
Read moreSafety & Dive Medicine11 min read
Asthma does not rule out scuba diving. What BTS, UKDMC, UHMS and SPUMS require: lung tests, exercise tests, peak flow limits and inhaler rules on dive days.
Read moreSafety & Dive Medicine8 min read
No training agency sets a body weight limit for scuba. What the medical form asks, where BMI cut-offs exist, what studies say about DCS, and gear sizes.
Read moreSafety & Dive Medicine8 min read
What a scuba dive briefing should cover: site, entry and exit, depth and time limits, turn pressure, signals, lost-buddy and emergency plans, with a checklist.
Read moreSafety & Dive Medicine8 min read
Is it safe to scuba dive right after a flight? Why there is no set waiting time, and how dehydration, jet lag, blocked ears and DVT shape your first dive day.
Read moreSafety & Dive Medicine9 min read
What a patent foramen ovale (PFO) means for divers: DCS risk figures, who the 2025 SPUMS/UKDMC statement says to test, and the options if you have one.
Read moreSafety & Dive Medicine8 min read
Why divers get decompression sickness inside table and computer limits: what DAN data show, the risk factors behind undeserved bends and how to lower the risk.
Read moreSafety & Dive Medicine10 min read
Decompression sickness symptoms and when they start, how DCS differs from gas embolism, and first aid in the right order, with DAN emergency numbers.
Read moreSafety & Dive Medicine9 min read
Nitrogen narcosis is the alcohol-like effect of breathing nitrogen under pressure: when it starts, what divers notice, what makes it worse and how to clear it.
Read moreSafety & Dive Medicine10 min read
Middle ear and inner ear barotrauma compared with swimmer's ear: causes, symptoms, which signs need urgent care, prevention on trips and return to diving.
Read moreSafety & Dive Medicine8 min read
Real travel insurance wording on scuba depth limits, what DAN and other dive accident plans pay for, hyperbaric and evacuation costs, and what to check.
Read moreSafety & Dive Medicine11 min read
How long to wait before flying after diving: 12 hours after one dive, 18 after several dives or days, 24+ after deco dives. DAN, US Navy and PADI compared.
Read moreSafety & Dive Medicine8 min read
What research says about panic in diving, early signs in you and your buddy, stop-breathe-think-act, and how to train out triggers such as mask flooding.
Read moreSafety & Dive Medicine10 min read
How the 2026 diver medical questionnaire works, which yes answers need a doctor's sign-off, what to bring to the appointment and how to find a dive doctor.
Read moreSafety & Dive Medicine8 min read
Scuba diving death rates from DAN reports and peer-reviewed studies, what causes fatal accidents, who is most at risk and the steps that lower it.
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