Blood clot on hand. Can be cured. tia?

My father had some gastric problem some days back coz of which we took him to the general hospital where the doc gave him a gastric injection after that he relived himself but a blood clot remains on his upper arm earlier we thought it will dissolve with the time but now its been almost a month has passed now and that clot is turning black and harder. I massaged him daily but he felt very pained when i touched it. I took the appointment of the doc for the same but he is scared and not ready to go for the check up. I am enclosing the pic of the clot. Now from the last couple of days he is complaining about the pain in his hand. I just want to know that a septic problem is not there and is there is any other remedy through which this can be cured. TIA