A bursa is a fluid filled structure - kind of like an airbag, that the body produces to provide a cushion to nearby structures.
Diagnosis, and differentiating it from a neuroma (swollen nerve) is quite hard to achieve without imaging, however is also not necessary.
The treatments for each problem are almost entirely the same, unless you are having surgery.
Although symptoms and problems in this region can be exceptionally painful for what they arae, I would recommend not rushing to surgery as the symptoms can be very easily managed with targeted treatment. Likewise, surgery is something which can both improve and worsen symptoms, so should really be used as a last resort in the event of symptoms being unrelenting despite good adherance to treatment plans.
Causes a sensation of numbness and tingling within the toes, a fullness or sensation of a rucked-up sock / marble under the forefoot and can be misdiagnosed as being a swollen nerve.