A cough is basically a reflex action so the airways can be cleared of phlegm, mucus and other irritants like dust and smoke. An inflammation of the upper respiratory tract due to a virus could also cause a cough.

Coughing can be symptomatic of many conditions including bronchitis, asthma, the common cold, flu, whooping cough or smoking. There are even some prescribed medicines that can cause coughing such as ACE-inhibitors which are used to treat heart failure.

Sometimes a cough can be a symptom of an underlying serious medical condition such as heart failure, lung cancer, tuberculosis, pneumonia or a pulmonary embolism (which is a clot on the lung). Coughs that have been caused by things like flu or the common cold normally disappear after a few days, but coughs that have been caused by an infection of the lung, such as bronchitis, could persist for several weeks, even after the infection has cleared up and this is due to the inflammation of the airways which usually take a while to clear up.

Cough Mechanism and Receptors

If someone has been suffering from a cough for more than a couple of weeks after having a viral infection, they should go to their doctor for medical advice.

Sciatica refers to any pain or compression of the sciatic nerve.  The sciatic nerve runs from the back of the pelvis and right down through the buttocks and both legs and ends at the feet. If something presses on the sciatic nerve it can cause a pain that runs from the lower back and down the leg; this pain can be mild to severe.

Sciatica

Causes of sciatica include slipped discs which can get temporarily moved out of place and then press on the sciatic nerve.  Acute sciatica is pain which lasts up to six weeks whereas chronic sciatica lasts longer than six weeks. Most cases clear up unaided but using painkillers, hot or cold compresses and exercise can help to alleviate symptoms. Sometimes there is a need to contact a physiotherapist especially for chronic sufferers.

Sciatic pain is different to back pain in that it also affects the legs.  Sciatica can cause weakness in the legs or feet. There is a rare condition which can cause sciatica and this is called Cauda Equine Syndrome.  This can lead to paralysis if left untreated as it can permanently damage the nervous system.  A sign of cauda equine syndrome is the sudden loss of bladder or bowel control and if this occurs immediate medical help should be sought.

Another cause of sciatica has been put down to general wear and tear.  This is why people over forty with jobs involving a physical activity are more prone to sciatica.

Drug allergies are adverse reactions to medication drugs and these reactions can be separated into three groups. First are those not actually related to the drug in question at all, but are coincidental and attributed to other mitigating factors associated with the illness or disease. Second are common predictable reactions like side effects related to taking other medication at the same time, or having an overdose. The third is unpredictable and uncommon reactions of which quite a few are allergic reactions that typically involve the immune system, being either immediate or delayed in reaction.

Allergic reactions can vary greatly from simple, slight rashes to very severe anaphylactic reactions of the immune system. Some drugs that can cause allergic reactions include heart drugs such as ACE inhibitors, antibiotics like penicillin, anesthetic drugs such as muscle relaxants, morphine, aspirin like drugs such as ibuprofen, chemotherapy drugs, antiseptics like iodine, vaccines such as tetanus, and colorings or preservatives in certain medications.

Reactions usually occur within one hour of taking the medication and can involve a measle-like rash that is very itchy. Some life threatening reactions may involve skin blistering with peeling accompanied by fever.

Common Allergic Reactions

Treatments of various drug allergic reactions involve the immediate withdrawal of the offending drug and then the administration of an antihistamine medicine. In severe allergic reactions, adrenaline and steroids may be used to save a life.