74 Year Old Has Low Sodium In Blood, Yet High Blood Pressure

Take him to a new doctor.

 

Hi,
Take him to a specialist on priority !!
Low sodium can result in him having a seizure attack & high BP in a stroke.....in both cases it can be dangerous. What does the BP reading show? Seizure is similar to an epileptic attack where the patient will not just have fits but also have muscle spasms & convulsions at the same time which will seem like a paralytic attack. Often during such attacks the patient suffers injuries/fractures/bruises etc in addition to the trauma. And Stroke as we all know can lead to brain damage & paralysis. So in both cases it is dangerous & the patient's trauma & suffering is definitely avoidable. The BP medication plus low salt diet results in this situation, so ask the doctor to adjust the dosage & bring him back to normal salt diet in consultation with the doctor & dietician.
My mother (76) was exactly in the same situation & despite being on medication suffered a massive seizure attack 2months ago. But luckily the hospital's QRT (quick response team) swung into action & rushed her into the emergency. Thankfully she is now recovering.
Mental stress /worries are big contributors & triggers for High BP..sometimes without any real reason....so keep him happy & engaged & don't give him time to brood.
keep playing some soothing music at home. Music has a calming effect & will help them sleep better which brings down BP considerably...its a proven natural therapy. People of that age generally suffer from loneliness & depression due which they keep brooding over (non)issues , developing negative mental patterns & end up with such diseases. It's up to us to break this pattern for them if we can recognize the cause on time.
All the best & take good care of him.

 

Go to an internal medicine specialist, preferably with good reviews. Look on Yelp, Angie's List, Healthgrades, RateMDs or ask friends/colleagues for recommendations.

 

My mother was looked after by a cardio & pulmonary specialist since she had developed other complications in addition to high BP & low sodium . And generally in a multi speciality hospital, they automatically refer to the concerned department/doctor.
At home, please ensure a happy environment with lots of socializing if possible,to keep him busy & active.
A tip : And if he is a TV addict, try to reduce the number of serials & news channels if possible as these days they seem to be major trigger factors for our seniors getting themselves worked up (I did that & it helped ...my mom was addicted to Crime Patrol & the likes...now none of that & her BP is stable LoL...)