The climber's lips and fingernail beds may turn blue. Likelihood of risks detailed at basecamp increase with greater severity. As higher altitude is achieved the risks of AMS severely increase. This means that the risk of AMS further progressing into HACE also rises. Headaches and sickness may last for days and can result with the person falling into a coma.
Most climbers experience spontaneous retinal hemorrhaging at some point during the expedition.
This is caused by increased blood flow through the vascular tissues of the eyes. Small clots form and can leak causing blood to seep behind the eyes. This can cause temporary blindness but it is not life threatening. Frostbite, dehydration, depression, impaired judgement, a drop off in breathing are always a risk. As a person gains altitude, their vulnerability to ASP, HACE and HAPE continues to increase.