14 General Kidney Infection Symptoms

2. Lower Back Pain

You may notice lower back pain when you have a kidney infection. This pain often feels dull or aching and is usually located on one or both sides of your back, just below the ribs. In some cases, it can spread toward your sides or lower abdomen.

When the kidneys are infected, they can swell and become tender, causing pain that feels deep and constant. Unlike muscle strain, which can improve with rest or gentle stretching, kidney pain often gets worse over time and does not improve. It commonly appears along with other symptoms such as fever, chills, nausea, or frequent urination.

Lower back pain can also result from common causes like poor posture, muscle strain, or long periods of sitting. However, when infection is the cause, the pain tends to persist and is often accompanied by signs of illness.

3. Yellowing of the Skin

Yellowing of the skin, also called jaundice, occurs when a yellow substance known as bilirubin builds up in the body. Bilirubin forms as old red blood cells break down. Normally, the liver filters it from the blood and removes it through bile, but sometimes appears alongside kidney problems.

An advanced kidney infection can impair liver or bile duct function, leading to a buildup of bilirubin, which causes yellowing of the skin and eyes. This change often appears first in the whites of the eyes or on the face before spreading to other areas. The color may range from light yellow to a deeper shade, depending on how much bilirubin is present. Conversely, liver-related issues that impair kidney function can lead to a buildup of bilirubin, resulting in yellow-tinged skin.

Some people also notice dark urine, pale stools, or increased tiredness alongside the color change. Jaundice is not a disease itself but a sign of an underlying problem. It can be linked to liver infections, blood disorders, blockages in the bile ducts, or advanced kidney infection.

4. Alcohol Toxicity

The kidneys and liver play a key role in removing toxins from the body, including substances like alcohol. When these organs are affected by an infection, their ability to process and filter toxins can be reduced. When the liver becomes overwhelmed, alcohol builds up in the bloodstream and begins to affect vital organs.

This means that even small amounts of alcohol may have a stronger effect, potentially causing unusually severe reactions or symptoms of alcohol intolerance. Early signs often include confusion, vomiting, or loss of coordination. As blood alcohol levels continue to rise, symptoms may worsen and lead to fainting, irregular heartbeat, or even coma. Alcohol is a depressant, and its effects can occur rapidly, especially if consumed on an empty stomach or mixed with other substances.

The severity of alcohol toxicity depends on how much and how fast you drink. Factors such as smaller body size, lack of food, or the use of certain medications can intensify its effects.

5. Burning When Urinating

You may notice a burning or stinging sensation when you urinate. This discomfort is a common sign of a urinary tract or kidney infection. It occurs when bacteria irritate the lining of the bladder or urethra, causing inflammation as urine passes through.

This symptom usually occurs with other urinary changes, like increased frequency of urination or a strong urge to urinate even when the bladder isn’t full. Some people also notice cloudy urine or a strong odor, which can signal infection in the urinary system. If bacteria travel upward from the bladder to the kidneys, the burning sensation may worsen.

It may be accompanied by pain in the lower back or sides, along with fever or chills as the infection spreads. At this stage, medical care is important to prevent complications.

6. Rashes

You might notice a rash during or after a kidney infection, although this is uncommon. When it does occur, the rash usually appears as red or purple spots, small raised bumps, or flat patches on the skin. These changes can develop suddenly and may affect areas such as the legs, arms, or torso.

One possible cause is inflammation related to the infection itself. In some cases, the immune response affects small blood vessels, leading to tiny red or purple spots known as purpura. These spots are often seen on the lower body and may not be itchy but can look alarming.

Another cause is an allergic reaction, most often to antibiotics or other medications used during treatment. Allergic rashes tend to look blotchy, spread quickly, and may itch or feel warm to the touch. Unlike inflammation-related rashes, these reactions often improve after the medication is adjusted or stopped.

7. Blood in Urine

You may notice blood in your urine when it appears pink, red, or brown. In some cases, the blood is not visible and is only found through a urine test. This can be an early sign of a kidney infection or another issue affecting the urinary tract.

Blood in the urine can come from the kidneys, bladder, or the tube that carries urine out of the body. When an infection is present, bacteria irritate the lining of the urinary system, which can lead to bleeding. Even a small amount of blood should not be ignored.

This symptom often occurs with others like pain or burning when urinating, frequent urges to urinate, fever, or lower back or side pain. While these symptoms commonly point to infection, they can also be linked to kidney stones or other urinary conditions.

8. Lowered Immunity

Your immune system helps protect your body from germs that cause infections. When your immune system weakens, it struggles to fight bacteria, increasing your risk of illnesses like kidney infections. A lowered immune system can result from medical conditions, certain treatments, or poor overall health.

When immune defenses are reduced, bacteria can spread more easily from the bladder to the kidneys. This can cause infections to last longer or lead to stronger symptoms such as fever, fatigue, or body weakness. People with diabetes, autoimmune conditions, or those receiving immune-suppressing treatments are often more vulnerable.

Signs of lowered immunity include frequent illness, slow wound healing, and unusual tiredness despite rest. Supporting your immune system can help lower the risk of kidney infection. Eating balanced meals, staying hydrated, washing hands regularly, and managing stress all help maintain immune strength.

9. Adrenal Response

Your adrenal glands sit on top of your kidneys and play an important role in how your body responds to stress and illness. They release hormones that help regulate energy levels, blood pressure, and immune activity. One of the main hormones involved is cortisol.

During an infection, including a kidney infection, your body signals the adrenal glands to produce more cortisol. This response helps control inflammation, maintain blood sugar levels, and keep you alert while your immune system fights the infection.

If the infection or physical stress lasts too long, the adrenal glands may struggle to keep up with the increased demand. When cortisol levels are not adequate, you may feel extreme fatigue, dizziness, low blood pressure, or weakness. People with adrenal insufficiency are especially vulnerable during serious infections.

When the adrenal response works properly, it supports immune balance and energy regulation. This coordinated system helps your body recover more efficiently and maintain stable functions during and after illness.

10. General Changes in Health

When your kidneys do not work properly, you may notice gradual changes in how your body feels day to day. These shifts often develop slowly, which makes them easy to overlook at first. Paying attention to small differences in energy, appetite, and overall comfort can help you recognize early signs that something may be wrong.

One of the first changes is increased fatigue. You might feel more tired than usual, even after adequate rest. When the kidneys cannot filter waste effectively, waste builds up in the blood and can leave you feeling weak or sluggish. Some people may also notice mild fever or chills as the body responds to infection or inflammation.

Digestive changes may follow. Appetite can decrease, food may taste different, or nausea may appear after eating small meals. In some cases, vomiting occurs as waste levels rise in the body. These symptoms can reduce interest in food without an obvious reason.

Physical changes may also become noticeable. Puffiness around the eyes in the morning or swelling in the hands and feet can signal fluid retention. Skin may feel dry or itchy as excess waste and minerals remain in the bloodstream.

11. Bad Smelling Urine

You might notice a strong or unusual odor in your urine from time to time. In many cases, this is harmless and related to what you eat or drink. Foods such as asparagus, coffee, or certain vitamins can temporarily change how urine smells. When you drink enough water, these odors usually fade quickly.

If the smell lasts longer or becomes unpleasant, dehydration may be the cause. Not drinking enough fluids leads to concentrated urine, which contains more waste and can produce a strong, ammonia-like odor. Persistent or foul-smelling urine can also signal an infection in the urinary tract or kidneys.

Certain odors may point to other health concerns. A sweet or fruity smell can be linked to high sugar levels in the urine, while a musty odor may relate to liver or metabolic conditions. If the odor continues or occurs with fever, back pain, or chills, it is important to seek medical attention.

12. Increase in Urine Frequency

When you have a kidney infection, you may notice the need to urinate more often than usual. This can be one of the earliest signs that your urinary tract is irritated or inflamed. The infection disrupts normal signals between the bladder and kidneys, creating a frequent urge to urinate even when the bladder is not full.

You may pass only small amounts of urine each time, and the urge can come on suddenly, including during the night. This disrupted pattern can interfere with sleep and lead to ongoing discomfort or fatigue. An increase in urine frequency often appears with other urinary symptoms. You may experience burning or pain during urination, pressure in the lower abdomen, or cloudy urine. These signs suggest that bacteria may be affecting the urinary system. If frequent urination occurs without increased fluid intake, it may point to an infection.

13. Persistent Urge to Urinate

You may notice a strong, frequent need to urinate, even when only a small amount of urine comes out. This urge often feels sudden and difficult to ignore and may wake you several times at night, a pattern known as nocturia.

This symptom can occur when the bladder becomes irritated or inflamed. With a kidney infection, bacteria moving up the urinary tract can trigger irritation, causing the bladder to send repeated signals that it needs to empty. As the body tries to flush out the infection, the urge to urinate may become more constant.

The persistent urge may appear along with other symptoms, such as a burning sensation during urination or pressure in the lower abdomen. In more severe cases, pain in the back or sides can also develop, suggesting that the infection may be affecting the kidneys.

14. Fever and Chills

You may notice fever and chills early when a kidney infection begins. This happens because your body raises its temperature to help fight the bacteria causing the infection. A fever, often above 100.4°F (38°C), supports your immune response by making it harder for germs to survive.

Chills commonly occur alongside fever as your body tries to generate and regulate heat. You might feel cold and begin to shiver even while your temperature is rising. These waves of shaking and warmth can come and go as your body works to control the infection. As fever and chills continue, you may start to feel tired, weak, or achy.

Fighting an infection requires extra energy, which can leave you feeling drained. Resting and drinking enough fluids help support your body during this process. If your fever is high or lasts more than a couple of days, you may have a spreading infection or one that isn’t improving.