Self diagnosis is often not a very good idea. You can scare yourself witless by doing that and at the end of it all, you may just have a sprain as you were diagnosed with !
Follow the Dr's instructions in all cases.
However, to answer your specific question which may assist others, here are some ways to treat mild Phlebitus.
•Keep active. Try to keep up with normal activities as much as possible.
•A hot flannel (cloth) placed over the vein. This may ease the pain.
•Painkilling tablets. Anti-inflammatory painkillers such as ibuprofen may ease the pain (but are not advised if you are pregnant). Paracetamol is an alternative. Some people may not be able to take anti-inflammatory painkillers. Check with your doctor or pharmacist.
•Anti-inflammatory creams or gels. An example is ibuprofen gel. These are an alternative if phlebitis is mild and only affects a small area of vein. They tend to produce fewer side-effects than those taken by mouth.
•Raising the affected leg. When you rest (when watching TV, or reading a book, etc), if you raise an affected leg so that your foot is higher than your hip, it helps to reduce swelling and discomfort. You can do this by lying on a sofa and putting the leg up on some cushions. When sleeping in bed, you can keep your leg raised by putting it on a pillow.
If you are concerned you should always discuss them with your GP.
