Metabolic acidosis is caused by increased production of hydrogen ions from metabolic causes or from excessive bicarbonate loss (pH ↓, HCO 3 − ↓). Compensatory mechanisms are: ■ ↓ pCO 2 by hyperventilation ■ ↓ H + by kidneys (unless in renal failure). Causes (all causes of metabolic acidosis require urgent assessment) Excessive production of h + ● Diabetic ketoacidosis ● Lactic acidosis secondary to hypoxia,…

The normal range of serum magnesium is 0.7–1.0 mmol Hypomagnesaemia refers to a serum level below 0.7 mmol Causes You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

Hypocalcaemia is a serum calcium of <2.1 mmol/L (normal range 2.1–2.6 mmol/L) with an ionised fraction <0.8 mmol Causes Associated with high serum phosphate ● Chronic renal failure ● Hypoparathyroidism ● Rhabdomyolysis ● Phosphate therapy You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

Hypercalcaemia is a serum calcium >2.62 mmol/L (normal range 2.1–2.6 mmol/L). It may be an asymptomatic laboratory finding. Symptoms usually become apparent with levels >3.50 mmol Causes ● Malignancy ■ Solid tumour with lytic bony metastases, e.g. Ca breast, bronchus ■ Solid tumours with humoral mediation, e.g. inappropriate PTH secretion with carcinoma of the bronchus, carcinoma of the kidney ■ Multiple myeloma ● Hyperparathyroidism (primary, secondary,…

The normal serum sodium level is 135–145 mmol Hyponatraemia refers to serum sodium levels of <135 mmol/L, and serum sodium of <120 mmol/L is considered severe. Causes Hypovolaemic ● Gastrointestinal losses ● Diarrhoea ● Vomiting ● Enterocutaneous fistula ● Renal sodium losses ● Diuretics ● Osmotic diuresis (e.g. hyperglycaemia) ● Renal failure ● Other sodium losses ● Burns ● Ascites ● Crush injuries ● Peritonitis You’re…

The normal serum sodium level is 135–145 mmol Hypernatraemia refers to a serum sodium level >145 mmol Causes Decreased water intake ● Confusion You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

Hypokalaemia is a reduced blood level of potassium <3.5 mmol Causes You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

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Hypoglycaemia is defined as a plasma glucose <2.5 mmol The actual glucose level at which symptoms develop varies markedly. Causes Drugs ● Insulin ● Sulfonylurea ● Alcohol ● Beta blockers ● Quinolones ● Pentamidine ● Quinine You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

Hyperglycaemia is defined as a plasma glucose >7.0 mmol By far the most common cause is diabetes mellitus. Causes Endocrine ● Diabetes mellitus (types 1 and 2) You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

Unintentional weight loss is often a manifestation of significant underlying disease and should never be ignored. Causes Systemic disease ● Malignancy ● Cardiac failure ● Chronic respiratory disease ● Renal failure ● Liver failure ● Malabsorption ● Connective tissue disease (e.g. SLE, rheumatoid arthritis) Endocrine ● Diabetes mellitus ● Hyperthyroidism ● Addison’s disease Infective ● TB • (very common in the developing world and on the…

Weight gain is extremely common and the most frequent cause is simple obesity. Excessive weight gain itself has deleterious effects on general health. With the exception of simple obesity and pregnancy, other conditions only account for ,1% of patients presenting with weight gain. Causes Increased fat ● Simple obesity ● Hypothyroidism ● Cushing’s syndrome ( Fig. 64 ) ● Polycystic ovarian syndrome ● Hypothalamic disease Increased…

Vomiting is the forceful ejection of gastric contents through the mouth. It occurs when the vomiting centre in the medulla oblongata is stimulated. This may be due to direct stimulation of the centre (central vomiting) or via afferent fibres (reflex vomiting). Haematemesis (vomiting blood) is dealt with in a separate chapter on p. 185. Causes Central vomiting ● Drugs, e.g. narcotic analgesics, chemotherapeutic agents ● Acute…

Voice disorders can be caused by a number of conditions. Change in the quality of the voice ranges from mild hoarseness to aphonia. It is important to exclude laryngeal carcinoma, which is easily treated in the early stages but has a poor prognosis once metastatic spread has occurred. Causes Infective ● Laryngitis Traumatic ● Blunt trauma ● Excessive vocal use Neoplastic ● Laryngeal papilloma (due to…

Patients who present with visual disturbance are often very distressed, with their quality of life affected, including their ability to drive. Below is a list of common conditions that may give rise to visual problems, grouped according to symptoms. Causes Visual disturbances (flashing lights or floaters) ● Migraine ● Retinal detachment ● Vitreous haemorrhage ● Age-related macular degeneration ● Vitreous detachment Blurring of vision ● Refractive…

Vaginal discharge can occur at any age but is usually a symptom of reproductive years. Causes ● Candidiasis ● Bacterial vaginosis ● Trichomonas vaginosis ( Fig. 60 ) ● Cervicitis, e.g. gonorrhoea, Chlamydia , herpes ● Excessive normal secretions ● Retained foreign body, e.g. tampon, pessary ● Intrauterine contraceptive device ● Salpingitis ● Infection of Bartholin’s glands ● Neoplasm, e.g. vagina, vulva ● Pyometra ● Colovaginal…

Retention of urine may be acute, chronic or acute-on-chronic. Patients with acute retention present as surgical emergencies. Acute retention is the sudden inability to pass urine, with the presence of painful bladder. Chronic retention is the presence of an enlarged, painless bladder with or without difficulty in micturition, which may be accompanied by overflow. Causes Local Urethral lumen or bladder neck ● Stones ● Blood clot…

Urinary incontinence is the involuntary loss of urine from the bladder. This has profound implications for patients quality of life including at times and places which are inconvenient, inappropriate and socially embarrassing. Stress incontinence is loss of urine during coughing or straining. Urge incontinence is the inability to maintain urinary continence in the presence of frequent and persistent urges to void. Overflow incontinence occurs when the…

Any inflammatory condition within the urethra may cause a discharge. It is important to diagnose sexually transmitted diseases so that appropriate treatment is given, not only to the patient but also to sexual contacts via contract tracing. Causes ● Prostatitis ● Non-gonococcal urethritis ● Chlamydia trachmatis ● UTI ● HSV ● Adenovirus ● Trichomonas vaginalis ● Mycoplasma genitalium ● Gonococcal urethritis ● Rare causes ● Coliforms…

A tremor is an involuntary rhythmic oscillation of a body part and usually refers to the movements around the small joints of the hands. Causes Resting tremor ● Parkinsonian tremor Action tremor ● Idiopathic ● Benign essential tremor ● Physiological ● Anxiety ● Exercise ● Chronic respiratory disease ● Thyrotoxicosis You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles…