How to prepare for laboratory tests

Preparing for laboratory tests correctly can sometimes seem complicated so Lifebrain has prepared a handbook for you to follow.

Blood collection

Fasting and diet

  • Fast for at least 8 hours before attending; do not consume sugary drinks, coffee and alcoholic drinks, and do not smoke cigarettes;
  • Do not make drastic changes to your daily diet (keep it as balanced as possible);
  • Do not eat large amounts of fat, carbohydrates and proteins.

Drug treatments

  • Do not undergo tests if you have been using drugs for a long period of time, which may alter the final results.

Physical activity

  • It is advisable not to engage in excessive physical activity in the 8 to 12 hours before the sample is collected as it may alter the results.

Urine culture

  • Take particular care of your intimate personal hygiene the evening before the analysis.
  • Pass the first stream of urine to eliminate the bacteria in the lower urinary tract and then collect the urine sample in the sterile container (available in pharmacies or available at our laboratories).
  • Ensure you deliver the container to the laboratory immediately; if this is not possible, store it in a cool and dry place to avoid any changes.

24-hour urine collection

  • Urinate into the designated container from early morning and continue throughout the day until the same time the next day;
  • The gradually collected urine should be kept in a cool, dry place;
  • Deliver the designated container to the laboratory.
  • For 24-hour urine collection, please contact the laboratory.

Cytological examination of the urine

  • Collect the second urine of the morning;
  • Repeat consecutively for three mornings, delivering the urine samples separately to the laboratory within 2 hours of collection each day.

Semen analysis

  • The seminal fluid sample must be collected in the laboratory and not elsewhere (except in specific psychological or logistical cases when this is not possible);
  • A period of abstention of three to five days prior to the collection of the sample is essential;
  • If the sample is collected in a place other than the laboratory, it must be delivered to the laboratory within 30 minutes of emission and stored at a constant temperature, avoiding changes in temperature.

Tests for detecting occult blood in the stools


  • It is advisable to eat a diet rich in roughage (salad, wholemeal bread, legumes, fruit and nuts) in the three days prior to the examination, to promote bleeding of the lesion;
  • The test should not be carried out during menstruation or if you have diarrhoea.
  • Collection of saliva sample
  • Tilt the neck forward and let the saliva slip into the special container.
  • For further information click here