If your sinuses are not blocked, they will equalize with your ears at the same time. So you don't need to do anything special to equalize the sinuses other than the ear equalization. However (for example, when you have a cold or flue), the air spaces in the sinuses can become blocked, preventing air passage.
AÅŸAs you go down, these air gaps get smaller. When the sinuses are out of sync, it can make itself felt as pain in your cheeks, eyes, forehead, teeth, and even jaw. If you continue to dive in such a difficult situation, your sinuses may bleed and fill with additional body fluid. In other words, our body develops a reaction against this situation. After diving, you can blow out excess nasal fluid or a bloody nasal fluid.
While diving, you may come across divers who regularly experience these problems and say that they are not bothered by it. However, trying to innocentize this abnormal situation does not mean that there is no problem.
The first rule is not to dive when you have a cold or your sinuses are full. If you think that your sinuses are blocked, you can try simple treatment methods and see that If they are OK. Steam application, which has a nasal opening and therapeutic feature, and specially produced apparatus in the form of pots or bottles for washing the sinuses may work. You can usually rinse the sinuses by filling them with warm salty water and putting in our nose in a suitable position. You should apply this without overdoing and without forcing it.
If you think you have a severe blockage, the best method is to consult an otolaryngologist(ear, nose, and throat doctor) and initiate the necessary treatment.
Some people use decongestants to clear their sinuses before diving. Decongestants are products with short-term effects and are produced for use in normal dry-land conditions. They may react differently during diving and may cause reverse blocking. For this reason, it is not the right behavior to use drugs and dive in any form and feature. Same for some pills or mixtures so far labeled as "Natural". The possible side effects of each drug can put you in a more difficult situation in water.. They can dry out mucous membranes, cause sleep and distraction, and cause more problems then their benefits.
As a general rule, It is hurting or If you feel it a lot, your body is telling you something isn't right. In this case, do not dive, if you do, stop and go back to shore and seek for appropriate treatment. It's always better to protect yourself than to try to heal later.