Krankschreibung vs. Krankenstand
Both Krankschreibung and Krankenstand are often translated as "sick leave" in English, but they refer to completely different aspects of being sick. The word Krankschreibung focuses on the medical document or the act of being officially signed off work by a doctor. On the other hand, Krankenstand describes the ongoing state of being absent from work due to illness, or the statistical sickness rate within a company or population.
Krankschreibung
The word Krankschreibung refers specifically to the doctor's note, the medical certificate, or the administrative act of a doctor officially declaring you unfit to work. It is used when talking about the proof of illness that you must provide to your employer or health insurance.
Ich muss die Krankschreibung heute noch bei meiner Arbeitsstelle einreichen.
(I still need to submit the sick note to my workplace today.)
Der Arzt hat mir nach der Untersuchung eine Krankschreibung für eine Woche gegeben.
(The doctor gave me a medical certificate for one week after the examination.)
Ab dem dritten Tag der Krankheit verlangt mein Chef eine offizielle Krankschreibung.
(From the third day of illness, my boss requires an official doctor's note.)
Sie hat die Krankschreibung digital an die Personalabteilung geschickt.
(She sent the sick note digitally to the human resources department.)
Ohne eine rechtzeitige Krankschreibung kann es Probleme mit der Gehaltsfortzahlung geben.
(Without a timely medical certificate, there can be issues with continued salary payments.)
Er bat die Ärztin um eine Krankschreibung, weil er starkes Fieber hatte.
(He asked the doctor to sign him off work because he had a high fever.)
Krankenstand
The word Krankenstand refers to the status or time period of being on sick leave, as well as the statistical number or percentage of employees who are currently off sick in a company. It focuses on the absence itself or the workforce data, rather than the medical document.
Wegen der starken Grippewelle haben wir aktuell einen sehr hohen Krankenstand in der Firma.
(Due to the severe flu wave, we currently have a very high sickness rate in the company.)
Nach einem langen Krankenstand kehrt sie nächste Woche endlich ins Büro zurück.
(After a long sick leave, she is finally returning to the office next week.)
Der Abteilungsleiter macht sich Sorgen über den steigenden Krankenstand in seinem Team.
(The department head is worried about the increasing number of sick employees in his team.)
Während eines Krankenstandes darf man Aktivitäten nachgehen, die der Genesung nicht schaden.
(During a sick leave, you are allowed to pursue activities that do not harm your recovery.)
Die Krankenkasse übernimmt die Zahlungen, wenn der Krankenstand länger als sechs Wochen dauert.
(The health insurance takes over the payments if the sick leave lasts longer than six weeks.)
Er befindet sich bereits seit Anfang des Monats im Krankenstand und muss sich schonen.
(He has been on sick leave since the beginning of the month and needs to rest.)
Summary
To summarize the difference, use Krankschreibung when you are talking about the physical doctor's note or the administrative act of getting signed off work. Use Krankenstand when you are referring to the ongoing status of being absent from work, the duration of that absence, or the overall statistical sickness rate within a workforce.