14 Known Symptoms of Endocarditis

2. Changes to Heart Rhythm

Endocarditis can disturb the heart’s normal rhythm by damaging the heart valves or nearby tissue. The infection and inflammation may interfere with the electrical signals that coordinate each heartbeat. Inflammation may also affect nearby parts of the heart’s electrical conduction system, including the pathways that help control the timing of each heartbeat.

When these pathways become irritated or compressed by swelling, the signals that regulate heart rhythm may become irregular. When a valve becomes infected, it may not open or close properly. As a result, the heart must work harder to move blood forward. This added strain on the heart can further disrupt the steady flow of electrical impulses and contribute to rhythm problems. In some cases, swelling or small clumps of infected material inside the heart can alter blood flow.

These changes can increase pressure within the heart and worsen disturbances in the normal heartbeat pattern. A person may notice a fast, slow, or uneven pulse. Some describe a fluttering feeling in the chest or a sense that the heart skips beats. These changes are called arrhythmias, meaning the heart does not beat in a regular pattern.

3. Fatigue, Aching Joints and Muscles

Fatigue is a common symptom of endocarditis. It develops as the body responds to an infection inside the heart. The immune system works continuously to fight bacteria or fungi in the bloodstream, and this process uses a large amount of energy. At the same time, ongoing inflammation can affect how efficiently the heart pumps blood.

Together, these changes can lower energy levels and leave the person feeling unusually weak or exhausted. As a result, the person may struggle with normal daily activities. Simple tasks such as walking, climbing stairs, or doing housework may require more effort than usual. Aching joints and muscles often appear alongside fatigue.

Inflammatory chemicals released during infection can affect muscles and joints, leading to soreness and stiffness. The pain may involve the knees, shoulders, back, or other large joints, and muscles may feel sore in a way similar to body aches during the flu.

4. Night Sweats

Night sweats are a common symptom of endocarditis. The condition begins when germs grow on the inner lining of the heart. As the infection develops, the immune system releases inflammatory chemicals that circulate through the bloodstream. These chemicals signal the brain’s temperature-regulating center to raise body temperature in an effort to fight the infection. This process leads to recurring fevers that may rise and fall over time.

When body temperature begins to drop, the body activates cooling responses. Blood vessels near the skin widen to release heat, and the sweat glands produce moisture to help lower body temperature. Because these temperature shifts often occur during sleep, a person may wake up with soaked sleepwear or damp sheets.

The sweating can feel heavy and may occur even when the room is cool. Unlike the brief sweating linked to a mild viral illness, night sweats from endocarditis may continue for days or weeks. The pattern can be irregular, with some nights worse than others, depending on fluctuations in fever and inflammation.

5. Shortness of Breath and Chest Pain When Breathing

Shortness of breath is a common symptom of endocarditis. The infection can damage heart valves and interfere with the normal flow of blood through the heart. When a valve does not open or close properly, the heart pumps blood less efficiently. Over time, this strain may cause blood to back up into the lungs.

As fluid builds up in lung tissue, breathing can feel difficult, tight, or labored. A person may notice becoming winded during simple tasks such as walking or climbing stairs. As the condition progresses, breathlessness can occur even at rest or while lying flat. Chest pain may occur when infection or inflammation affects tissues around the lungs or the heart.

If the lining around the lungs becomes irritated, breathing movements can cause sharp pain that worsens with deep breaths or coughing. Chest discomfort can indicate stress on the heart, often feeling like pressure or squeezing that may spread to the arm, jaw, or back.

6. Swelling in the Feet and Legs

Swelling in the feet and legs can develop when endocarditis damages the heart valves and interferes with normal blood flow. When a valve does not function properly, the heart cannot pump blood forward as effectively. Over time, blood may back up in the veins, increasing pressure inside the blood vessels.

This pressure pushes fluid out into nearby tissues. Because gravity pulls fluid downward, it often collects in the ankles, feet, and lower legs. The skin may appear puffy or stretched, and shoes or socks may feel tighter than usual. This type of swelling is called edema. Pressing a finger into the swollen area may leave a small dent that fades slowly.

The legs may also feel heavy, tight, or uncomfortable. In more advanced cases, fluid can collect in the abdomen as well. Swelling often appears along with other signs of reduced heart function, such as shortness of breath or fatigue.

7. Malaise

Malaise is a general feeling of being unwell. In endocarditis, it often appears early as germs begin growing on the inner lining of the heart and trigger an ongoing infection. As the infection develops, the immune system releases inflammatory chemicals into the bloodstream to help fight the invading bacteria or fungi.

These substances travel through the body and can affect the brain and nervous system, leading to feelings of illness. At the same time, the constant immune response requires energy and can disrupt normal body functions. As a result, a person may feel low energy from the start of the day and sense that they “just do not feel right.”

Simple tasks such as walking, cooking, or getting dressed may feel harder than usual. Rest does not always improve the feeling because the underlying infection continues to drive inflammation. The same inflammatory response can also reduce appetite and alter metabolism. Over time, these changes may lead to unintended weight loss.

8. Uncommon Symptoms

Endocarditis causes small clumps of infected material or inflammatory debris to break loose and travel through the bloodstream. These particles can lodge in small blood vessels in different parts of the body, where they may block blood flow or trigger localized bleeding and inflammation.

Skin changes are one possible result. A person may notice small red or purple spots on the palms or soles that are usually painless and may fade over time. Others may develop tender, red bumps on the fingers or toes that hurt when touched. Small dark lines may also appear under the fingernails, caused by tiny areas of bleeding in the nail bed.

Similar changes can occur in the eyes. Small spots of bleeding may develop in the white part of the eye. Although vision changes are uncommon, they may occur if blood flow to parts of the eye becomes affected. If these particles travel to the kidneys, they may disrupt normal filtering and lead to blood in the urine.

The urine may appear pink, red, or brown, signaling possible kidney involvement. When clots reach the brain, they can interrupt blood supply to certain areas. This may cause numbness or weakness on one side of the body. In rare cases, confusion or trouble speaking can develop.

9. Petechiae

Petechiae are small red, purple, or brown spots that appear on the skin. They are flat and do not fade when pressed. These spots form when tiny blood vessels under the skin leak a small amount of blood. In endocarditis, infection on the inner lining of the heart can release small clots or inflammatory debris into the bloodstream.

As these tiny particles travel through the circulation, they may lodge in very small blood vessels and damage delicate capillaries. This damage allows small amounts of blood to seep into the surrounding skin, producing petechiae. The spots can appear on the chest, arms, or legs. They may also show up inside the mouth, on the whites of the eyes, or as small dark streaks under the fingernails.

On darker skin, they may look deep brown or purple rather than red. Petechiae often develop along with other symptoms such as fever, fatigue, or night sweats. The spots themselves usually do not hurt or itch, so a person may not notice them right away.

10. Osler’s Nodes

Osler’s nodes are small, painful lumps that appear under the skin, most often on the pads of the fingers or toes. They are usually red, purple, or darker than the surrounding skin. In infective endocarditis, bacteria or fungi can form infected growths on the inner lining of the heart.

Tiny clots or infection-related particles may break loose from these areas and travel through the bloodstream. When they lodge in small blood vessels in the skin, they trigger a localized immune reaction that causes swelling, tenderness, and the formation of a raised lump. Some people notice pain in the area before the lump becomes visible.

Once the lump forms, the tenderness can make it uncomfortable to use the fingers or walk. Osler’s nodes are not common, but they are a recognized sign of infective endocarditis. They tend to appear in cases that develop gradually over weeks rather than suddenly. Other symptoms, such as fever, fatigue, or joint pain, may occur at the same time.

11. Janeway Lesions

Janeway lesions are small, flat spots that appear on the palms of the hands or the soles of the feet. They are usually red or bluish-red and do not cause pain. In acute infective endocarditis, bacteria can grow on damaged heart valves and form infected growths.

Tiny clumps of bacteria and debris may break loose from these areas and enter the bloodstream. As these septic microemboli travel through the circulation, they can lodge in very small blood vessels within the skin. When these particles settle in the vessels, they may cause localized infection and mild damage to the vessel walls.

This process leads to the formation of visible flat spots on the skin. Because the changes mainly occur within the small blood vessels rather than in the surrounding tissue, Janeway lesions usually remain painless. They often appear as smooth patches that do not itch or feel tender when pressed, so a person may not notice them right away.

12. Pain in the Spleen

Pain in the spleen can develop when endocarditis allows infected clumps of cells or small clots to travel through the bloodstream. These particles can lodge in the blood vessels that supply the spleen, an organ located under the left ribs above the stomach.

When a vessel becomes blocked, blood flow to part of the spleen decreases. This reduced circulation can injure the tissue and cause swelling. As a result, a person may feel a dull or sharp pain in the upper left side of the abdomen. In some cases, the pain can spread to the left shoulder due to shared nerve pathways.

The spleen plays an important role in filtering blood and helping the body fight infection. If bacteria reach the spleen, they can form small pockets of infection called abscesses. This can increase inflammation and make the area tender, especially when a doctor presses on the left upper abdomen.

13. Blood in Urine

Blood in the urine, also called hematuria, can appear in some people with endocarditis. The urine may look pink, red, or brown. In other cases, the bleeding is microscopic and only detected on a laboratory test. In endocarditis, bacteria form infected growths on the inner lining of the heart.

Small clumps of bacteria, blood cells, and debris may break loose from these areas and travel through the bloodstream. When these particles reach the kidneys, they can lodge in tiny blood vessels and irritate nearby tissue. The kidneys contain microscopic filtering units called glomeruli that remove waste from the blood while keeping blood cells inside the circulation.

When infection-related particles affect these delicate structures, circulation in the small vessels may be disrupted. At the same time, the body’s immune response to infection can trigger inflammation in the glomeruli. This inflammation can weaken the filtering barrier that normally prevents blood cells from leaving the bloodstream. As a result, red blood cells may leak into the urine. A urine test may also detect protein or other signs of kidney stress.

14. Unexplained Weight Loss

Unexplained weight loss can occur in people with endocarditis, even when they have not changed their diet or activity level. It is often described as losing about 10 pounds, or roughly 5% of body weight, within 6 to 12 months without trying. In endocarditis, the loss may develop more quickly, sometimes over several weeks as the infection persists.

The process begins with a long-lasting infection inside the heart. As the body fights the infection, the immune system releases inflammatory chemicals into the bloodstream. These substances influence metabolism and increase the body’s overall energy demands.

Ongoing inflammation and fever can speed up metabolism, causing the body to burn more calories than usual. These inflammatory signals may also encourage the body to break down stored fat and muscle to supply additional energy during infection. At the same time, symptoms such as fever, night sweats, fatigue, and reduced appetite may lower food intake. When the body uses more energy but takes in fewer calories, gradual weight loss can occur.