weak/compromised immune systems, lymphatic systems and/or one or more compromised *organs*, particularly the pancreas, liver, kidneys and/or spleen, a tendency to contract any number of bacterial or fungal infections, especially if they go systemic will all make the pH issue extremely important even though your body will do anything and everything it can to keep your blood in a *normal* range... even to the point of sacrificing your bones, organs, cause feelings of shortness of breath, etc.
increasingly... fungal infections are killing people... just as they have been in insects, amphibians, fish, birds, and more recently mammals. Just a few short years ago it was an extreme medical rarity to see these things in humans - let alone kill them... however it is an ever escalating issue because of the continual environmental degradation.
keep your house clean and dry too... and free of things like carpet etc. to minimize places of bacterial and/or fungal accumulation.
I know this from personal experience (sister passed away within 4 weeks of a **correct** diagnosis with a fungal infection) and in asking lots of questions of a team of over 15 doctors just last month.
getting the digestive system working well from mouth to anus through diet, and/or herbs/supplements if necessary is perhaps the best single thing anyone can do to help their health outside of exercise. Focus on that.
Make sure that you have normal bowel movements and complete digestion with no discomfort at all - each and every meal. *We* have control over that... not any doctor.