Thank you for writing to Doctor Spring.
It would be better stop doing yoga or any strenuous activity until this settles down.Lump in the spine which is not painful could be due to various reasons like epidermal cyst/ sebaceous cyst/ lipomas. All these conditions are very common and are very simple to treat.
Cysts either epidermal or sebaceous need puncture to let the discharge out , while lipoma does not require any treatment unless for cosmetic reasons surgical excision can be considered.
Other serious reasons for a lump in the spine could be due to bone cysts/ tumors either benign or malignant/nerve tissue tumor etc. These conditions present with numbness, tingling , painful limbs and the lump itself could be painful and growing in size.
As, you have noticed it after doing yoga it could be related to strain in the muscles too. Even common epidermal cyst or sebaceous cyst or lipoma could be causing it. These conditions present with a painless lump which is soft.
But in your case as the lump is hard, not growing in size and painless, so it could be due to injury to soft tissues/hematoma or a ligament sprain which can cause minimal discomfort.
It requires examination and certain investigations like plain x ray spine and further confirmation might also need MRI and biopsy of the lump tissue(in case of suspicion of tumor, which is a rare possibility).
There is no need to worry, as you do not have any warning signs but get examined by your GP for necessary treatment depending upon the cause.
Hope this helps. Do write to me for follow ups.
Patient replied :
Thank you for your help!
All the best,
Wish you good health, happy holidays.