Around 1,500 people are diagnosed with endocarditis each year. This uncommon condition involves an infection within the heart’s chamber lining and valves that harms the heart and can prove fatal, according to the British Heart Foundation.

Early diagnosis and treatment is crucial to prevent deadly complications. But many of its warning signs may appear completely unrelated to cardiac issues. One such indicator is an alteration in your fingernails.

The charity describes these as “unusual dark lines under your fingernails”. These are also referred to as splinter haemorrhages, manifesting as reddish-brown streaks running along your nail’s growth direction and occur when minute blood clots harm the tiny vessels beneath your nail.

Physical trauma, such as accidentally knocking your nail, can also trigger this, alongside conditions like diabetes or certain medications, including aspirin, which may cause the clots. Nevertheless, if this pattern repeats across several nails without injury or other clear triggers, it’s advisable to consult a GP.

Other visible signs of endocarditis include:

• Small dark-coloured spots on the skin
• Red lumps on the fingers or toes that may be painful
• Pale skin

More typical symptoms can prove trickier to spot as they may resemble minor ailments like flu. The condition can also progress over weeks or months, making detection even more challenging, whilst some individuals might begin experiencing symptoms suddenly.

The BHF urged: “Infective endocarditis can be fatal if left untreated. Therefore, early detection and prompt management are critically important. You should contact your healthcare provider as soon as possible if you recognise the above symptoms.”

Endocarditis can typically be managed with antibiotics and overseen through routine GP visits and blood examinations.

In some instances, surgical intervention may be required to fix heart damage or eliminate any abscesses that have developed.

Should the infection and resulting heart damage go without treatment, it may result in heart failure. It can also heighten your stroke risk.

The charity highlighted that individuals can also lower their endocarditis risk primarily by maintaining proper hygiene, especially regarding oral, dental and hand cleanliness. This reduces the likelihood of bacteria entering the bloodstream via the mouth or skin from infections in these regions.

You might be at a higher risk of endocarditis if you have:

• Heart valve disease
• An artificial heart valve
• Had endocarditis before
• Congenital heart disease
• Hypertrophic cardiomyopathy
• Injected drugs into your veins