Periodontitis is an inflammatory disease that is caused by bacterial plaque. If it is not treated, the damage to the structures holding the teeth in place continues below the gum line, invisible from the outside. This is precisely why you cannot detect periodontitis on your own.
However, you can observe some signs of gum inflammation (gingivitis) yourself, for example, the gum line can be discolored red or dark red and be somewhat swollen and you may also notice bleeding gums when you brush or floss your teeth. For smokers, it is important to know that your gums tend to bleed less, and you may be mistaken in your self-assessment of periodontitis*.
On the other hand, there are the following signs of periodontitis that you can see yourself: Like gingivitis, the gums may also be somewhat swollen and reddened. However, since there has already been bone loss in the jawbone, the teeth may have already shifted somewhat, and open spaces formed between the teeth. In advanced periodontitis, the teeth may become loose the bacterial plaque would cause bad breath.