Bed bugs are among the most troublesome household pests, and their presence has little to do with whether a home is clean or dirty. They can be found in houses, apartments, dormitories, hotels and even luxury resorts, usually travelling unnoticed in luggage, clothing, bags, bedding or furniture. The common bed bug, Cimex lectularius, is a small wingless insect with a flat, oval body. Adults are typically around 5 millimetres long, while the US Centers for Disease Control and Prevention gives a size range of approximately 1 to 7mm across different stages. Their colour ranges from yellowish-brown to reddish-brown, becoming darker and more swollen after feeding. Bed bugs feed on the blood of humans and animals, usually at night. During a bite they inject substances with anaesthetic and anticoagulant effects, which is why people often do not feel the bite when it happens. Marks may not appear until one or several days later, and some people develop no visible reaction at all. When reactions occur, bites can be red, raised and itchy and may appear in groups or lines. Bite marks alone, however, are not reliable proof of a bed bug infestation because mosquito and flea bites, skin conditions and other reactions can look very similar.
More reliable evidence can usually be found around the sleeping area. Mattress seams and folds, bed frames and headboards, gaps in furniture, cracks, areas behind pictures and loose wallpaper are common hiding places. Warning signs include live insects, shed skins, small dark faecal spots and rusty or reddish blood stains on mattresses and sheets. Their eggs are tiny, measuring around 1mm. Bed bugs can squeeze into extremely narrow spaces and survive for months without a blood meal, which helps explain why established infestations can be so difficult to eliminate. Importantly, finding bed bugs does not indicate poor hygiene. They can enter an exceptionally clean home simply by hitching a ride in a suitcase or piece of furniture.
From a health perspective, there is both reassuring and concerning news. The CDC and US Environmental Protection Agency say bed bugs are not known to transmit diseases to humans. That does not make them harmless. Their bites can cause intense itching, while repeated scratching can lead to secondary skin infections. Severe allergic reactions are possible, although rare. Persistent infestations can also cause insomnia and anxiety, with some people becoming afraid to sleep or repeatedly checking their beds during the night. In exceptionally severe and prolonged infestations, repeated blood feeding can also contribute to clinically significant blood loss, but this is not the expected consequence of ordinary isolated bites.
For bites, the UK’s NHS recommends keeping the affected skin clean, avoiding scratching and applying something cool, such as a clean damp cloth, to reduce itching and swelling. A pharmacist may recommend an antihistamine or mild steroid cream when itching is troublesome. Most bites clear by themselves within about a week. Medical advice should be sought if pain, swelling or redness continues to worsen, there are signs of infection or a serious allergic reaction develops. Eliminating the insects themselves is usually the more difficult task. The NHS recommends washing affected bedding and clothing at 60°C and tumble drying them on a hot setting for at least 30 minutes. Regular cleaning and vacuuming can help detect an infestation early, but once bed bugs have become established, household measures alone may not be enough. Their ability to hide and the resistance of some populations to insecticides mean professional pest control is often the safest approach. Travellers can reduce the risk by keeping luggage away from hotel beds, inspecting mattress seams and checking suitcases and clothing after returning home. Bed bugs do not choose their hosts according to how clean their homes are – they simply need somewhere to hide and a human or animal from which to obtain a blood meal.
