How do I know if my hiccups are normal?

Hi doctor,

One day I suddenly started having hiccups after I ate or drank something. Nothing was significantly different from the day before to the day after that I am aware of. It could be just a tiny glass of water with absolutely nothing else, and this will cause sporadic hiccups for about 20 minutes. It could be a couple of crackers or anything in small amounts. Even in small amounts. The first year it occurred, the hiccups were persistent and forceful and lasted longer - maybe upwards of an hour (even just drinking water). In the past year, they have decreased to 15 to 20 minutes of hiccups after consuming any liquid or food. This happens every time. I have mentioned it to two different primary care physicians that told me not to worry about it, and they did not have any follow-up questions. Common causes of hiccups that do not apply to me: I do not eat too quickly, the amount consumed does not matter - even a small amount will produce hiccups, I am not under stress or excitement that would cause them, carbonation and alcohol are not a factor, the temperature and spice of the food or beverage is not a factor, I am not swallowing any more air than I did previous to not having hiccups two years ago. The current prescriptions I am on are the same ones that I have been on before this started two years ago (Aldactone and Levothyroxine). I do not have diabetes. My blood pressure and cholesterol are good. My electrolyte balance is within the normal range. I have had a lot of chiropractic adjustments in the past couple of years due to an injury in my L5-S1 lumbar spine (adjustments are from the top of the spine to the bottom). I do not have any central nervous disorders that I am aware of, like meningitis, encephalitis, or multiple sclerosis. I have not had abdominal surgery in the past two years.

Is this anything to be concerned about or to further investigate, or should I not worry about having hiccups forever-more after every time I drink or eat? If the hiccups are purely hiccups, then I am happy to deal with them. However, I want to ensure that it does not sound like the signs of something more severe as a cause. I have been looking for similar descriptions in my case in my online searches.

Thank you for your time.