Any party to a lawsuit who received an unfavorable ruling from a court can file an appeal. Someone who is not a party to the suit does not have authority to file an appeal. Also, as discussed in an earlier post, there generally must be a final order entered before an appeal can be filed.
Although any aggrieved party is entitled to file an appeal, it may not always be advisable to do so. Statistically speaking, most cases that are appealed are not reversed; the trial court decision is upheld. This is because on appeal, the court is looking for errors made by the lower court.
On issues of fact — what the trial court determined the facts of the case were — trial court is given deference. Unless it can be shown that there was no substantial evidence to support the trial court’s factual determinations, the trial court’s rulings on issues of fact will be upheld.