If someone scratches the skin of his boil or pimple and he sees some blood or pus underneath it, and it remains in the same place without flowing out, wudhu will not break. But if it flows out, wudhu will break.
If a wound is very deep, then as long as the blood or pus from it remains there and does not come out and flow onto the body, wudhu will not break.
If the blood of a sore does not come out on its own, but is forced out, then wudhu will also break if it flows.
If blood oozes out of a wound and it is covered with some dust, or dabbed with a cloth, and again it oozes out, and again he dabs it – and this is done repeatedly – then he should think for himself and deduce that had he not dabbed at it, the blood would have flowed, and therefore wudhu would break. And even if he did dab at it, it would not have flowed, then wudhu will not break.
Someone notices blood in his saliva: if the blood is very little and the colour of the saliva is whitish or yellowish, wudhu will not break. But if the blood is equal to or more than the saliva, and the saliva is reddish in colour, wudhu will break.
If something is bitten with the teeth and a blood stain is found on that thing, or if the teeth were brushed and some redness is seen on the brush – and despite all this no blood or redness is seen in the saliva then wudhu will not break.
If one is bitten by a leech and so much of blood flows into it that if the leech is dissected, blood will begin to flow, wudhu will break. But if the leech has sucked out very little blood, wudhu will not break. If a mosquito, fly, bee, or bug sucks out blood, then wudhu will not break.