2 Answers

An episode of tendonitis may only last for a few days. However, sometimes it can be more persistent and last for several weeks or months.
There are a number of different treatment options, although what's best for you may depend on which tendon you have injured.
Self care

You can treat tendonitis yourself at home using the self care techniques described below.
Rest the tendon

Stop doing the activity that caused tendonitis, such as sport or typing, or at least reduce the amount you do. This will help prevent any further inflammation or damage.
It's important to rest the affected area to allow the inflammation to settle. Some form of support, such as a bandage, splint or brace, may help by reducing movement.
How long you need to rest for may depend on which tendon is affected and how severely it is damaged. For example, if you have golfer's elbow, which causes pain in the middle of your elbow, you may need to rest your elbow for at least six weeks.
Ice packs

Applying an ice pack to the affected area may help ease the pain and swelling. Do not put ice directly on your skin because it may cause a cold burn. Instead, wrap it in a towel or put a towel over the injured area before applying the ice pack. A bag of ice cubes or frozen vegetables wrapped in a towel works just as well.
Hold the ice pack on the affected area for around 15-20 minutes several times a day. You can also use an ice pack after exercise to try to prevent symptoms occurring.
Painkillers

Tendonitis can be treated with mild non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.
NSAIDs provide short-term pain relief and help reduce inflammation. They are available as a medicine that you swallow or as a gel that you apply directly to the affected area.
NSAIDs should not be used for long periods and are not recommended for people with asthma, kidney disease or liver disease.
Other painkillers, such as paracetamol, will also help ease the pain. For more severe pain, a stronger painkiller, such as codeine, can be prescribed.
Dietary supplements

Some people have reported that their tendonitis symptoms improved after taking dietary supplements, such as amino acids. However, as yet, there is no scientific evidence to show that these supplements have any benefits.
Therapies and injections

Physiotherapy

Physiotherapy (physio), uses massage and manipulation to help recover movement and function in the affected areas. There are many different physiotherapy techniques including:
special exercises to stretch and strengthen the tendon and surrounding muscles
massaging the affected area
using high-frequency sound waves (ultrasound)
using narrow beams of light (lasers)
Physiotherapy can be used to relieve pain and may result in more long-term improvement than corticosteroid injections (see below).
Corticosteroid injections

Corticosteroids are medicines that contain steroids (a type of hormone) and can be used to reduce inflammation. If there is inflammation, corticosteroids can be injected around the affected tendon or into the tendon sheath.
Although corticosteroid injections can relieve pain, they do not have a long-term effect and the pain often returns. You can have another injection, but you will need to wait at least six weeks. It is not possible to have more than three injections into the same area in a year because it can increase the risk of the tendon rupturing (splitting).
Thinning and lightening of the skin are two possible side effects of corticosteroid injections.
Local anaesthetic injections

Local anaesthetic is often used during minor surgical procedures to numb a specific area of the body. In some types of tendonitis, local anaesthetic can be injected into the affected area as well as corticosteroids.
Extracorporeal shock wave therapy

Extracorporeal shock wave therapy (ESWT) is a treatment option for tendonitis that has not responded to other treatments.
ESWT involves passing shock waves through your skin to the affected area. This may be carried out over one or more sessions and local anaesthetic may be used to numb the area first.
ESWT may help relieve the pain caused by tennis elbow or Achilles tendonitis, but it is not clear whether it is better than other treatment options. If you are considering this treatment, you may be asked to take part in a clinical trial (medical research) to look at how effective the treatment is over time. There are also possible risks, such as:
the tendon rupturing - in one study, this happened to 2 out of 49 people who had ESWT for Achilles tendonitis
temporary redness or swelling
pain during the treatment
feeling sick
The National Institute for Health and Care Excellence (NICE) has produced guidelines about the use of:
ESWT for calcific tendonitis (PDF, 31Kb)
ESWT for tennis elbow (PDF, 53Kb)
ESWT for Achilles tendonitis (PDF, 53Kb)
Surgery

Surgery may be a possible option for some types of tendonitis. However, most cases of tendonitis improve with time so surgery is not usually necessary. You may want to try other treatments for up to a year before considering surgery.
Tennis elbow

Several different surgical techniques have been used for tennis elbow including:
removing a damaged part of muscle from the elbow
removing part of a ligament in your elbow (ligaments are tough bands of tissue that link two bones together at a joint)
damaging a nerve in your elbow so that you no longer feel pain there
The benefits of surgery for tennis elbow have yet to be proven. Your symptoms may improve but this could be because the condition was getting better anyway, or it may be due to the placebo effect (when you feel better after having a 'dummy' treatment rather than a 'real' treatment).
After surgery, you should be able to start playing sport again within 4-6 months.
Calcific tendonitis

Surgery can be used to remove calcium deposits that have formed in the tendon in your shoulder. This can be carried out using a technique called an arthroscopy.
An arthroscopy is a type of keyhole surgery that can be used to look inside a joint and repair any damage. Only a very small cut needs to be made in your body.
Biceps tendonitis

Biceps tendonitis affects the tendon that attaches the muscle on the front of your upper arm (bicep) to your shoulder.
Surgery can be used to reattach the end of the tendon to the bone in your upper arm (humerus). This may be an option if you are in severe pain or you have torn the tendon.

http://www.nhs.uk/Conditions/Tendonitis/Pages/Treatment.aspx

Don’t use it or use as little as possible.  Take anti-inflamitories as directed.  Warm baths can be soothing.  Alternate heat and cold packs…….