Regular O2 is between 95-100% for a healthy adult. A drop below this is cause for concern, but not until it drops below 90%. When this happens, take the patient to the hospital immediately. Several treatments can be undertaken to restore the patient’s health: Asthma can be a cause of this condition, and thus medication for asthma treatment can be administered. Inhalers can also be used en route to the hospital if available. - Doctors usually use a face mask or nasal pipe to deliver the required oxygen. It cannot be done on your own since the medical oxygen is different from the standard gas tanks used in other fields. - If infections like the one in pneumonia are the cause, antibiotics may be administered. - Steroids are commonly used to reduce inflammation due to respiratory deficiency. - When the situation gets out of hand, drastic measures are taken. They include either oxygen through a hyperbaric chamber or on a ventilator. This step is usually taken when the brain has been damaged too far.