Brief Answer:
Should be evaluated to rule out, chronic sinusitis, gastric reflux, ulcer

Detailed Answer:
Hi
Welcome.
I have gone through your query.

A confirmed diagnosis is not possible on net but I’ll try and narrow down the diagnosis for you. You need to discuss these options with your doctor.

You can have a region of darker spot compared to rest of mucosa if you have chronic sinusitis. This will cause post nasal drip. Some of it may stick to the back of the throat and appear as dark spot. It could also be inflammation due to post nasal drip.

Another possibility of it may be by gastric reflux. This can be controlled with medications and life style changes such as avoiding spicy, oily food or alcohol or smoking etc and eating regularly on time and eating healthy food.

The spot could also be a chronic ulcer. If it looks like an ulcer then yes, this needs to be investigated. Some ulcers appear due to poor hygiene or chemical burn due to acid from gastric reflux or iron and vitamin deficiency (responds to iron and vitamin supplementation). If the ulcer persists and does not heal then it needs to be investigated.

Regarding the tongue it sounds like normal variation and I feel it is nothing serious. But if possible, you can upload the pictures for better assessment.

I would recommend you to see your healthcare provider for primary examination. Meanwhile I would recommend you to maintain high degree of oral hygiene. I would have asked you to use chlorhexidine mouth wash twice daily morning and before going to bed, salt water gargaling two to three times daily. I would have decided on the need of medication based on the examination.

This provisional advice provided by me is based entirely on the input provided to me. I would suggest examination by the doctor.

I hope this suggestion might be of some help to you.
Take care.

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