Symptoms of kidney infection

The symptoms of a kidney infection usually develop quite quickly over a few hours or days.
Common symptoms include:

Pain and discomfort in your side, lower back or around your genitals
High temperature (it may reach 39.5C or 103.1F)
Shivering or chills
Feeling very weak or tired
Loss of appetite
Feeling sick or being sick
Diarrhoea

You may have other symptoms if you also have cystitis or urethritis (an infection of the urethra). These additional symptoms may include:

Pain or a burning sensation during urination
Need to urinate frequently or urgently
Feeling that you’re unable to urinate fully
Blood in your urine
Cloudy or foul smelling urine
Pain in your lower abdomen

Children
Children with a kidney infection may also have additional symptoms, such as:

A lack of energy
Irritability
Poor feeding and/or vomiting
Not growing at the expected rate
Abdominal pain
Jaundice (yellowing of the skin and whites of the eyes)
Blood in the urine
Unpleasant smelling urine
Bedwetting

When to seek medical advice
Contact your doctor if you have a high temperature, persistent pain, or if you notice a change to your usual pattern of urination. Contact your doctor immediately if you think your child may have a kidney infection. If you have blood in your urine, you should always see your doctor so the cause can be investigated. Kidney infections require prompt treatment with antibiotics to help relieve symptoms and prevent complications developing. Your GP can carry out some simple tests to help diagnose a kidney infection.

Source: NHS UK

http://www.nhs.uk/Conditions/Kidney-infection/Pages/Symptoms.aspx