In a civil case, you have missed your court date due to extenuating circumstances and default judgment has been entered against you, you may be able to appeal the judgment made at the original court hearing. The court will only allow an appeal at its discretion, depending on whether or not they consider your extenuating circumstances to be valid. Therefore, it is important to submit any supporting evidence that you may have with your appeal, in order to show that your failure to attend court on the relevant date was unavoidable.
If your court summons was in relation to a crime of a serious nature and you failed to attend court on the required date, the court may issue a warrant for your arrest. Once you have either surrendered yourself or have been arrested, you may be taken into custody and held there until your next court date and possibly until the case goes to trial (if your bail is withdrawn). If you are in the process of an appeal, you may be able to pay a fee in order to avoid being kept in prison whilst you are awaiting the outcome of your appeal.