Fantail goldfish with lump on head

Question
My friend's fantail goldfish has one lump in the middle of its head for a few days. The lump is red at the bottom and purple at the top. I have done a bit of research into conditions such as fish pox but none of the conditions seems to fit the symptoms. What could this lump be and is it causing the fish harm?

Answer
Hey Emma,

On a medical level, the lump could be a ruptured vessel near it's brain causing massive swelling and pain, or it could be a lump on the noggin from crashing into stuff.

Keep track of his lump, watch it to see if it worsens, reddens, more appear, or if anything seems to change. My guess is it's probably a bruise or a vessel rupture, or something you cant really medicate for of similar nature. It does not strike me as any sort of disease or condition that would be considered "easily curable" and a simple bottle of medication from a pet store would fix this.

If you want to insure the best odds of recovery, and comfort, raise the salt level in the tank to 1.005 (about 1 tablespoon per 10 gallons). Set the temperature to 65*f exact. Make sure the water quality is pristine, perfect, and otherwise heavenly. Do a complete water test, adjust everything to neutral (or in goldfish tanks pH 6.3-6.7, ammonia, nitrite, nitrate 0ppm, no chlorine, no iron, slightly soft water, etc). With excellent water, at a good temperature, all thats left is feeding. Switch to brine shrimp once a day, and cut peas once a day. If they are currently being fed only once a day, then feed brine one day, peas the next. Try to adjust any power head filters in ways that reduce high current (if there are powerheads in the tank) and be sure to turn the tank lights off every night for atleast 8 hours.

It seems odd that there'd be a mystery bump after caring for a fish for long periods of time, but like you said it does not quite fit any disease I've heard of. Ill do further research into it and post a follow up (it will email you automatically when i do) with any new developments i discover. If not, then simply continue with above mentioned things.

Best wishes, and hope your friend's fish get better!