Hay fever is not only caused by grass pollen. Many people suffer in the spring with a snuffly nose, sore, watering eyes and itchy throat, which are triggered by allergy to tree pollens. Alder pollen is released as early as February, but the main tree allergy season starts mid March, when birch trees flower, then oak, plane and ash bloom during April. Pollen counts can rise steeply over a few days, causing severe symptoms in susceptible people but antihistamine medicines can bring prompt relief. Birch pollen is similar to proteins in apples, pears, peaches and plums, and people who get spring hay fever may find their lips swell if they eat them raw. Cooking alters the protein, so try them in pies and jam instead.

Irritable Bowel Syndrome (IBS) can cause abdominal pain, constipation, bloating and diarrhoea. Orthodox medicines aim to ease spasm of the bowel muscles, but may only partially relieve these symptoms. Many experts believe that psychological factors can play a large role in digestive function and treatments to calm the mind can be very helpful in easing a troubled gut. Research at King's College Hospital showed effective treatments for IBS included anti-depressants (even for those not outwardly depressed), and Cognitive Behaviour Therapy. For those especially affected by symptoms, hypnosis, targeting links between brain and bowel, and relaxation were shown to be very helpful.

My 10-year-old daughter has nightmares and wakes up very scared. She is otherwise well, has good friends and seems happy at school. Does she need therapy?
Jan Thompson, Oxford

Nightmares in children are common. Sometimes they are linked to a stressful event, such as an argument or fight, so ask if she has any worries. But often the reason is unclear and they're not linked to any emotional disturbance. Unfortunately, they can lead to bedtime fears, so reassure her that the events in her mind are just dreams, and nothing to do with real life. It may help to stop her reading scary stories, or watching frightening programmes on TV, and ensure a calm, relaxing bedtime routine. Don't let her stay up late, as tiredness can make them worse.

I had a heavy cold recently and felt so bad I had to take time off work. I’m on the mend, but still have a runny nose and feel very tired. Am I still infectious?
Jerome Collins, Croydon

Colds are caused by viruses, and spread to others by coughs, sneezes, and contaminated fingers passing the virus to nose and mouth. Thus it is possible to catch a cold from touching infected door handles and keyboards. You are most infectious at the start of a cold when you begin to sneeze and cough, and far less as the symptoms improve. Cold victims should make sure they practise very careful ‘respiratory hygiene’. Turn your head away from others and remember to cover your mouth and nose with a tissue when you cough and sneeze, and wash your hands afterwards.

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